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TABLE OF CONTENTS
TABLE OF CONTENTS

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-132606

The information contained in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement is notan offer to sell nor does it seek an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED JUNE 2, 2008

PRELIMINARY PROSPECTUS SUPPLEMENT
(To prospectus dated March 21, 2006)

              Shares

GRAPHIC

State Street Corporation

Common Stock

          We are offering shares of our common stock, par value $1.00 per share. Our common stock is listed on the New York Stock Exchange under the symbol "STT". On May 30, 2008, the last reported sale price of our common stock on the New York Stock Exchange was $72.02 per share.

          Our common stock is not a deposit or other obligation of a bank and is not insured by the FDIC or any other government agency.

          Your investment in our common stock involves risks. You should read "Risk Factors" beginning on page S-8 of this prospectus supplement so that you better understand those risks before buying common stock.

          Neither the Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities or passed on the accuracy or adequacy of this prospectus supplement. Any representation to the contrary is a criminal offense.

 
   Per Share
   Total
Public offering price   $   $
Underwriting fees   $   $
Proceeds, before expenses, to State Street Corporation   $   $

          The underwriters have an option to purchase up to an additional            shares of common stock within 30 days of the date of this prospectus supplement.

          The underwriters expect to deliver the common stock in book-entry form only through the facilities of The Depository Trust Company against payment in New York, New York on                         , 2008.

Goldman, Sachs & Co.   Morgan Stanley
 
Credit Suisse Lehman Brothers UBS Investment Bank

The date of this prospectus supplement is                        , 2008.

TABLE OF CONTENTS

Prospectus Supplement

 
   Page

About This Prospectus Supplement
 
S-1
Forward-Looking Statements   S-2
Prospectus Supplement Summary   S-4
Risk Factors   S-8
Use of Proceeds   S-23
Price Range of Common Stock and Dividends   S-24
State Street Capitalization   S-25
Certain U.S. Federal Tax Consequences To Non-U.S. Holders   S-26
Certain ERISA Considerations   S-30
Underwriting   S-32
Validity of Securities   S-36
Experts   S-36
Where You Can Find More Information   S-37

Prospectus

 
   Page
About This Prospectus   1
Where You Can Find More Information   1
Incorporation of Certain Documents by Reference   1
Forward-Looking Statements   2
Risk Factors   3
State Street Corporation   7
Consolidated Ratios of Earnings to Fixed Charges   8
Use of Proceeds   8
Description of Debt Securities   8
Description of the Trusts   17
Description of the Junior Subordinated Debentures   18
Description of the Capital Securities   30
Common Securities   41
Description of the Capital Securities Guarantees   41
Relationship among the Capital Securities, the Corresponding Junior Subordinated Debentures and the Capital Securities Guarantees   44
Description of Preferred Stock   46
Description of Depositary Shares   49
Description of Common Stock   51
Description of Stock Purchase Contracts And Stock Purchase Units   53
Description of Warrants   53
Global Securities   54
Plan of Distribution   61
Validity of Securities   62
Experts   62

i


ABOUT THIS PROSPECTUS SUPPLEMENT

          This document consists of two parts. The first part is the prospectus supplement, which describes the specific terms of this offering. The second part is the prospectus, which describes more general information, some of which may not apply to this offering. You should read both this prospectus supplement and the accompanying prospectus, together with additional information described under the heading "Where You Can Find More Information" on page S-37.

          In this prospectus supplement, "State Street", "we", "our", "ours" and "us" refer to State Street Corporation, which is a financial holding company headquartered in Boston, Massachusetts, and its subsidiaries on a consolidated basis, unless the context otherwise requires. References to "State Street Bank" mean State Street Bank and Trust Company. If the information set forth in this prospectus supplement differs in any way from the information set forth in the accompanying prospectus, you should rely on the information set forth in this prospectus supplement.

          Currency amounts in this prospectus supplement are stated in U.S. dollars.

          You should rely only on the information contained in or incorporated by reference into this prospectus supplement and the accompanying prospectus or information contained in a free writing prospectus that we authorize to be delivered to you. This prospectus supplement may be used only for the purpose for which it has been prepared. No one is authorized to give information other than that contained in this prospectus supplement and in the documents referred to in this prospectus supplement and which are made available to the public. We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it.

          We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should not assume that the information appearing in this prospectus supplement or any document incorporated by reference is accurate as of any date other than the date of the applicable document. Our business, financial condition, results of operations and prospects may have changed since that date. Neither this prospectus supplement nor the accompanying prospectus constitutes an offer, or an invitation on our behalf or on behalf of the underwriters, to subscribe for and purchase, any of the securities and may not be used for or in connection with an offer or solicitation by anyone, in any jurisdiction in which such an offer or solicitation is not authorized or to any person to whom it is unlawful to make such an offer or solicitation.

S-1


FORWARD-LOOKING STATEMENTS

          This prospectus supplement, the accompanying prospectus and the documents incorporated by reference contain statements that are considered "forward-looking statements" within the meaning of United States securities laws. In addition, State Street and its management may make other written or oral communications from time to time that contain forward-looking statements. Forward-looking statements, including statements about industry trends, management's future expectations and other matters that do not relate strictly to historical facts, are based on assumptions by management, and are often identified by such forward-looking terminology as "expect", "look", "believe", "anticipate", "estimate", "seek", "may", "will", "trend", "target" and "goal", or similar statements or variations of such terms. Forward-looking statements may include, among other things, statements about State Street's confidence in its strategies and its expectations about financial performance, market growth, acquisitions and divestitures, new technologies, services and opportunities and earnings.

          Forward-looking statements are subject to various risks and uncertainties, which change over time, are based on management's expectations and assumptions at the time the statements are made, and are not guarantees of future results. Management's expectations and assumptions, and the continued validity of the forward-looking statements, are subject to change due to a broad range of factors affecting the national and global economies, the equity, debt, currency and other financial markets, as well as factors specific to State Street Corporation and its subsidiaries, including State Street Bank.

          Factors that could cause changes in the expectations or assumptions on which forward-looking statements are based include, but are not limited to:

S-2

          Therefore, actual outcomes and results may differ materially from what is expressed in our forward-looking statements and from our historical financial results due to the factors discussed above, below and elsewhere in this prospectus supplement, the accompanying prospectus or in our other Securities and Exchange Commission, or SEC, filings. Forward-looking statements should not be relied upon as representing our expectations or beliefs as of any date subsequent to the date this prospectus supplement is filed with the SEC except to the extent required by law. State Street undertakes no obligation to revise the forward-looking statements contained in this prospectus supplement to reflect events after the date it is filed with the SEC. The factors discussed above and in the "Risk Factors" section, beginning on page S-8, are not intended to be a complete summary of all risks and uncertainties that may affect our businesses. Though we strive to monitor and mitigate risk, we cannot anticipate all potential economic, operational and financial developments that may adversely impact our operations and our financial results.

          Forward-looking statements should not be viewed as predictions, and should not be the primary basis upon which investors evaluate State Street or our common stock. Any investor in State Street should consider all risks and uncertainties disclosed in our filings with the SEC described under the Section entitled "Where You Can Find More Information" on page S-37, all of which are accessible on the SEC's website at www.sec.gov.

S-3


PROSPECTUS SUPPLEMENT SUMMARY

          This summary highlights information contained elsewhere in, or incorporated by reference into, this prospectus supplement and the accompanying prospectus. As a result, it does not contain all of the information that may be important to you or that you should consider before investing in our common stock. You should read this entire prospectus supplement and accompanying prospectus, including the "Risk Factors" section and the documents incorporated by reference, which are described under "Where You Can Find More Information" on page S-37.


State Street Corporation

          State Street Corporation is a financial holding company organized under the laws of The Commonwealth of Massachusetts. Through our subsidiaries, we provide a full range of products and services for institutional investors worldwide.

          We were organized in 1970 and conduct our business primarily through our principal bank subsidiary, State Street Bank. State Street Bank traces its beginnings to the founding of the Union Bank in 1792. The charter under which State Street Bank now operates was authorized by a special act of the Massachusetts Legislature in 1891, and its present name was adopted in 1960.

          With $14.90 trillion of assets under custody and $1.96 trillion of assets under management at March 31, 2008, we are a leading specialist in meeting the needs of institutional investors worldwide. Our customers include mutual funds and other collective investment funds, corporate and public retirement plans, insurance companies, foundations, endowments and other investment pools, and investment managers. Including the United States, we operate in 26 countries and more than 100 geographic markets worldwide.

          Our common stock is listed on the New York Stock Exchange under the ticker symbol "STT". Our executive offices are located at One Lincoln Street, Boston, Massachusetts 02111, and our telephone number is (617) 786-3000.


Risk Factors

          An investment in our common stock involves certain risks. You should carefully consider the risks described in the "Risk Factors" section beginning on page S-8 of this prospectus supplement, as well as other information included or incorporated by reference into the accompanying prospectus, including our consolidated financial statements and the notes thereto, before making an investment decision.

S-4


Selected Consolidated Financial Highlights

 
   Quarters Ended(1)
   Years Ended
  
(Dollars in millions, except per share amounts
or where otherwise noted)
   March 31,
2008(2)
   March 31,
2007
   December 31,
2007(6)
   December 31,
2006
  
Total fee revenue   $ 1,961   $ 1,370   $ 6,633   $ 5,186  
Net interest revenue     625     325     1,730     1,110  
Gains (Losses) related to investment securities, net     (9 )   1     (27 )   15  
    Total revenue     2,577     1,696     8,336     6,311  

Salaries and employee benefits
 
 
1,062
 
 
739
 
 
3,256
 
 
2,652
 
Other operating expenses     712     474     3,177     1,888  
   
Total operating expenses(3)(4)
 
 
1,774
 
 
1,213
 
 
6,433
 
 
4,540
 
Income tax expense     273     169     642     675  
Income from continuing operations     530     314     1,261     1,096  
Income from discontinued operations     —     —     —     10  
    Net income     530     314     1,261     1,106  

Diluted earnings per share(5):
 
 
 
 
 
 
 
 
 
 
 
 
 
  From continuing operations     1.35     0.93     3.45     3.26  
  From discontinued operations     —     —     —     0.03  
  Net income     1.35     0.93     3.45     3.29  
Cash dividends declared per share     0.23     0.21     0.88     0.80  

Return on equity from continuing operations
 
 
18.7
%
 
17.4
%
 
13.4
%
 
16.2
%
Return on equity     18.7 %   17.4 %   13.4 %   16.4 %

Average shares outstanding (in thousands):
 
 
 
 
 
 
 
 
 
 
 
 
 
  Basic     387,942     334,036     360,675     331,350  
  Diluted     393,647     338,727     365,488     335,732  

Assets under custody (in trillions)
 
$
14.90
 
$
12.33
 
$
15.30
 
$
11.85
 
Assets under management (in trillions)     1.96     1.85     1.98     1.75  
(1)
Information for the quarters ended March 31, 2008 and March 31, 2007 is unaudited.

(2)
Quarter ended March 31, 2008 includes financial results of Investors Financial, which State Street acquired on July 2, 2007.

(3)
Total operating expenses for the quarter ended March 31, 2008 and the year ended December 31, 2007 include merger and integration costs of $26 million and $198 million, respectively, recorded in connection with the acquisition of Investors Financial.

(4)
Total operating expenses for the year ended December 31, 2007 include a net charge of $467 million, or $279 million after-tax, associated with certain active fixed-income strategies managed by State Street Global Advisors.

(5)
Diluted earnings per share for the quarter ended March 31, 2008 and the year ended December 31, 2007 reflect the issuance of approximately 60.8 million shares on July 2, 2007 in connection with the completion of the acquisition of Investors Financial.

(6)
Financial results for the year ended December 31, 2007 include results of Investors Financial for the quarters ended September 30 and December 31, 2007.

S-5


Pro Forma Capital Ratio Presentation

          For illustrative purposes, the following table sets forth our specified capital ratios as of March 31, 2008, (1) as reported, (2) as adjusted to give effect to the receipt of $2.4 billion of net proceeds from this offering and (3) as adjusted to give effect to the receipt of $2.4 billion of net proceeds from this offering and to reflect the effects if we were to consolidate all assets and liabilities of the four third-party-owned, special-purpose, multi-seller asset-backed commercial paper programs that we administer, commonly referred to as "conduits", onto our consolidated balance sheet in accordance with Financial Accounting Standards Board Interpretation No. 46(R).

 
   As of March 31, 2008
  
 
   As Reported
   As Adjusted for
Receipt of Net
Proceeds(1)
   As Adjusted for
Receipt of Net
Proceeds and
Conduit
Consolidation
(1)(2)(3)
  
Tier 1 leverage ratio   6.1 % 7.8 % 6.7 %
Tier 1 risk-based capital ratio   12.4   16.0   13.8  
Total risk-based capital ratio   13.8   17.4   15.2  
Tangible common equity to tangible assets (TCE/TA)   2.9   4.6   3.0  
(1)
Assumes $2.4 billion of net proceeds from this offering (after deducting estimated expenses and underwriting discounts and commissions).

(2)
Assumes that all of the conduits, with total assets of approximately $28.3 billion as of March 31, 2008, are consolidated on March 31, 2008 and that the assets of the conduits are recorded at fair value with an assumed marginal tax rate of 40%. We have historically placed a high level of reliance on information obtained from third-party sources to measure fair values. Third-party sources use assumptions, judgments and estimates in determining securities values, and different third parties may provide different prices for securities. Moreover, depending upon, among other things, the measurement date of the security, the subsequent sale price of the security may be different from its recorded fair value. These differences may be significant especially if the security is sold during a period of illiquidity or market disruption or as part of a large block of securities under a forced transaction.

(3)
The degree of impact of consolidation on our tier 1 leverage ratio would depend on how and when consolidation occurred, since this ratio is a function of our consolidated total average assets over an entire quarter.

          A hypothetical increase or decrease in tangible shareholders' equity of $100 million would increase or decrease our reported capital ratios at March 31, 2008, all other factors remaining unchanged, as follows: (a) tier 1 leverage ratio by seven basis points, (b) tier 1 risk-based capital ratio by 15 basis points, (c) total risk-based capital ratio by 15 basis points and (d) TCE/TA by seven basis points. A hypothetical increase or decrease in total assets of $1.0 billion would decrease or increase our reported capital ratios at March 31, 2008, all other factors remaining unchanged, as follows: (a) tier 1 leverage ratio by four basis points, (b) tier 1 risk-based capital ratio by eight basis points, (c) total risk-based capital ratio by nine basis points and (d) TCE/TA by two basis points. In calculating the impact of an increase or decrease in assets on the capital ratios, we have assumed that the assets are risk-weighted based on the actual composite risk weighting at March 31, 2008.

S-6


The Offering

Common stock we are offering:               shares
Common stock outstanding after this offering:               shares(1)(2)
Underwriter's option to purchase additional shares:               shares
Use of proceeds:   We expect to receive net proceeds from this offering of approximately $2.4 billion (or approximately $2.8 billion if the underwriters exercise in full their option to purchase additional shares, after expenses and underwriting discounts). We intend to use the net proceeds from this offering for general corporate purposes.
New York Stock Exchange symbol:   "STT"
(1)
The number of shares of our common stock outstanding immediately after the closing of this offering is based on 390,960,437 shares of our common stock outstanding as of May 30, 2008, including unvested restricted stock granted under our stock compensation plans.

(2)
Unless otherwise indicated, the number of shares of common stock presented in this prospectus supplement assumes no exercise by the underwriters of their option to purchase additional shares and excludes 14,814,521 shares issuable upon exercise of options outstanding as of May 30, 2008 and 9,190,779 shares issuable pursuant to outstanding grants under stock award programs, other equity incentive plans and a stock purchase plan as of May 30, 2008.

S-7


RISK FACTORS

          An investment in our common stock is subject to the risk factors described below. You should carefully consider the following risk factors and other information contained in this prospectus supplement, in the documents incorporated by reference in this prospectus supplement and in the accompanying prospectus before deciding whether this investment is suited to your particular circumstances.

          The risk factors below update the risk factors set forth in our Quarterly Report on Form 10-Q for the quarter ended March 31, 2008, particularly those (a) under the heading "Liquidity Risk", concerning accounts managed by SSgA that have the benefit of contractual arrangements with third-party financial institutions known as "wrap providers", (b) under the heading "Operational Risk", concerning the maintenance of confidential information; and (c) under the heading "Regulatory/Legal/Accounting/Tax Risk", concerning legal actions, regulatory matters and tax matters.


Risks Related to State Street

Business Conditions/Economic Risk

          Our businesses are affected by global economic conditions, political uncertainties and volatility and other developments in the financial markets. Factors such as interest rates and commodities prices, regional and international rates of economic growth, inflation, political instability, the liquidity and volatility of fixed-income, equity, credit, currency, derivative and other financial markets, and investor confidence can significantly affect the financial markets in which we and our customers are engaged. Such factors have affected, and may further unfavorably affect, both regional and worldwide economic growth, creating adverse effects on many companies, including us, in ways that are not predictable or that we may fail to anticipate.

          A significant market downturn may lead to a decline in the value of assets under management and custody, which could reduce our asset-based fee revenue and may adversely impact other transaction-based revenue, such as securities finance revenue, and the volume of transactions that we execute for our customers. This market downturn could be accompanied by a widening of credit spreads or credit deterioration, which could reduce the value of securities we hold in our investment portfolio. The assets held by our asset-backed commercial paper conduits can be similarly affected. In addition, lower market volatility, even in a generally rising market environment, may reduce trading volumes of our customers, and our ability to achieve attractive spreads, which could lead to lower trading revenues. Our revenues, particularly our trading revenues, may increase or decrease depending upon the extent of increases or decreases in cross-border investments made by our customers. The level of cross-border activity can be influenced by a number of factors, including geopolitical instabilities and customer mix. General market downturns would also likely lead to a decline in the volume of transactions we execute on behalf of our customers, decreasing our fee and revenue opportunities and reducing the level of assets under management and custody. Market performance and volatility may also influence the revenue that we receive from off-balance sheet activities.

          In addition, revenues during a calendar year, driven by the products and services we provide, can fluctuate commensurate with the normal course of business activity of our customers and market conditions, and may provide volatility to our earnings from quarter to quarter.

          In recent years, investment manager and hedge fund manager operations outsourcing and non-U.S. asset servicing have been areas of rapid growth in our business. If the demand for these types of services were to decline, we could see a slowdown in the growth rate of our revenue.

Strategic/Competition Risk

          We expect the markets in which we operate to remain both highly competitive and global across all facets of our business, resulting in increases in both regional and global competitive risks. We have

S-8


experienced, and anticipate that we will continue to experience, pricing pressure in many of our core businesses. Many of our businesses compete with other domestic and international banks and financial services companies, such as custody banks, investment advisors, broker/dealers, outsourcing companies and data processing companies. Many of our competitors, including our competitors in core services, have substantially greater capital resources. In some of our businesses, we are service providers to significant competitors. These competitors are in some instances significant customers, and the retention of these customers involves additional risks, such as the avoidance of actual or perceived conflicts of interest and the maintenance of high levels of service quality. The ability of a competitor to offer comparable or improved products or services at a lower price would likely negatively affect our ability to maintain or increase our profitability. Many of our core services are subject to contracts that have relatively short terms or may be terminated by our customer after a short notice period. In addition, pricing pressures as a result of the activities of competitors, customer pricing reviews, and rebids, as well as the introduction of new products, may result in a reduction in the prices we can charge for our products and services.

          Our strategy for growth depends upon both attracting new customers and cross-selling additional products and services to our existing customer base. To the extent that we are not able to achieve these goals, we may not be able to attain our financial goals. Substantial risks and uncertainties are associated with the introduction of new products and services, including technical and control requirements that may need to be developed and implemented to offer such products while also managing associated risks. The introduction of new products and services can also entail significant time and resources. Regulatory and internal control requirements, capital requirements, competitive alternatives and shifting market preferences may also determine if such initiatives can be brought to market in a manner that is timely and attractive to our customers. Failure to successfully manage these risks in the development and implementation of new products or services could have a material adverse effect on our business, as well as our results of operations and financial condition.

          Our financial performance depends, in part, on our ability to develop and market new and innovative services and to adopt or develop new technologies that differentiate our products or provide cost efficiencies, while avoiding increased related expenses. The risks we face include rapid technological change in the industry, our ability to access technical and other information from our customers, and the significant and ongoing investments required to bring new products and services to market in a timely manner at competitive prices. Our proactive cross-selling of multiple products and services to our customers can exacerbate the negative financial effects associated with the risk of loss of any one customer. Developments in the securities processing industry, including shortened settlement cycles and straight-through processing, have required continued internal procedural enhancements and further technology investment.

          Acquisitions of complementary businesses and technologies, development of strategic alliances and divestitures of portions of our business, in addition to fostering organic growth opportunities, are an active part of our overall business strategy to remain competitive. We may not be able to effectively assimilate services, technologies, key personnel or businesses of acquired companies into our business or service offerings, alliances may not be successful, and we may not achieve related revenue growth or cost savings. In addition, we may not be able to successfully manage the divestiture of identified businesses on satisfactory terms, if at all, and this would reduce anticipated benefits to earnings. Ongoing consolidation within the financial services industry could pose challenges in the markets we serve.

          Acquisitions present risks that differ from the risks associated with our ongoing operations. Our financial results for 2008 and for the next few years may be significantly impacted by our ability to achieve the cost savings and other benefits that we anticipate as a result of the acquisition of Investors Financial in 2007, as well as our ability to retain its customer base and to successfully cross-sell our products and services to its customers. These cost savings and customer retention goals will be

S-9


significantly influenced by our ability to convert former Investors Financial customers onto State Street systems in a timely manner and to maintain the level of customer service such customers received from Investors Financial. Future acquisitions may present similar integration, cost savings and customer retention challenges.

          Intellectual property of an acquired business, such as Currenex, Inc., acquired in 2007, may be an important component of the value that we agree to pay for such a business; however, these types of acquisitions entail the risk that the acquired business does not own the intellectual property that we believe we are acquiring, that the intellectual property is dependent upon licenses from third parties, that the acquired business infringes upon the intellectual property rights of others, or that the technology does not have the acceptance in the marketplace that we anticipated. Acquisitions of investment servicing businesses such as Investors Financial normally entail information technology systems conversions, which involve operational risks and may result in customer dissatisfaction and defection. Customers of businesses that we acquire, including, in the case of Investors Financial, its largest customer, are competitors of our non-custody businesses. The loss of some of these customers or a significant reduction in revenues generated from them, for competitive or other reasons, would adversely affect the benefits that we expect to achieve from the acquisition.

          Our ability to acquire other entities that provide our core services to achieve greater economies of scale or to expand our product offering is dependent upon our financial resources and our ability to access the capital markets. Due to company-specific issues or lack of liquidity in the capital markets, our ability to continue to expand through acquisitions or to dispose of businesses that no longer are strategic to us may be adversely affected.

          In connection with most acquisitions, before the acquisition can be completed, we must obtain various regulatory approvals or consents, which may include approvals of the Federal Reserve Board, the Massachusetts Commissioner of Banks and other domestic and foreign regulatory authorities. These regulatory authorities may impose conditions on the completion of the acquisition or require changes to its terms. Any such conditions, or any associated regulatory delays, could limit the benefits of the transaction.

          With any acquisition, the integration of the operations and resources of the businesses could result in the loss of key employees, the disruption of our and the acquired company's ongoing businesses, or inconsistencies in standards, controls, procedures and policies that could adversely affect our ability to maintain relationships with customers and employees or to achieve the anticipated benefits of the acquisition. Integration efforts may also divert management attention and resources. The acquisition and combination of a business with our operations may also expose us to risks from unknown or contingent liabilities with respect to which we may have no recourse against the seller. While we normally seek to mitigate that risk through pre-acquisition due diligence, increasingly acquisition transactions are competitive auctions in which we have limited time and access to information to evaluate the risks inherent in the business being acquired, and no or limited recourse against the seller if undisclosed liabilities are discovered after we enter into a definitive agreement.

          We may not achieve the benefits we sought in an acquisition, or, if achieved, those benefits may be achieved later than we anticipated. Failure to achieve anticipated benefits from an acquisition could result in increased costs and lower revenues than expected of the combined company. In addition, if the financial performance associated with an acquisition falls short of expectations, it may result in impairment charges associated with the goodwill or other intangible assets recorded as part of the acquisition.

Liquidity Risk

          The management of liquidity risk is critical to the management of our consolidated balance sheet and to our ability to service our customer base. In managing our consolidated balance sheet, our

S-10


primary source of funding is customer deposits. These deposits are predominantly short-term, transaction-based deposits by institutional investors. Our ability to continue to attract these deposits, and other funding sources such as certificates of deposit and commercial paper, is subject to variability based upon a number of factors, including volume and volatility in the global securities markets, our credit rating and the relative interest rates that we are prepared to pay for these liabilities.

          In managing our consolidated balance sheet, we also depend on access to global capital markets to provide us with sufficient capital resources and liquidity to meet our commitments and business needs, and to accommodate the transaction and cash management needs of our customers. Other sources of funding available to us, and upon which we rely as regular components of our liquidity risk management strategy, include inter-bank borrowings, repurchase agreements and borrowings from the Federal Reserve discount window, or comparable non-U.S. central banking sources. Any occurrence that may limit our access to the capital markets, such as a decline in the confidence of our corporate debt or equity purchasers, or a downgrade of any of our credit ratings, may adversely affect our capital costs and our ability to raise capital and, in turn, our liquidity. Similarly, the failure to maintain acceptable credit ratings may preclude us from being competitive in certain products. General market disruptions, natural disasters or operational problems may affect either third parties or us, and can also have an adverse affect on our liquidity. We generally use our sources of funds to invest in a portfolio of investment securities and to maintain the liquidity necessary to extend credit to our customers. These funds are invested in a variety of assets ranging from short-term interest-bearing deposits with banks to longer-maturity investment securities. While we have historically maintained our investment portfolio at a relatively short duration with respect to interest-rate risk, the average maturity of the investment portfolio is significantly longer than the contractual maturity of our deposit base. In addition, as part of our custody business, we provide overdraft financing to our customers, and liquidity lines to third-party commercial paper conduits and mutual funds, as well as more traditional extensions of credit. The demand for credit is difficult to forecast and control, and may be at its peak at times of dislocation in the securities markets, potentially compounding liquidity issues.

          In a period of financial disruption, or if negative developments occurred with respect to State Street, the availability and cost of our funding sources could be adversely affected. In that event, our cost of funds may increase, thereby reducing our net interest revenue, or we may need to dispose of a portion of our investment portfolio, which, depending upon market conditions, could result in our realizing a loss or experiencing other adverse accounting consequences upon those dispositions. Our efforts to monitor and manage liquidity risk may not be successful or sufficient to deal with dramatic or unanticipated changes in the global securities markets or other State Street or market event-driven reductions in liquidity.

          At March 31, 2008, including the effect of master netting agreements, approximately $78.28 billion of our consolidated total assets and approximately $9.10 billion of our consolidated total liabilities were carried at fair value. Of the total assets carried at fair value, approximately $68.01 billion consisted of investment securities available for sale, with the remainder primarily composed of derivative instruments. More than 90% of the available-for-sale securities and substantially all of the derivative instruments were categorized in level 2 of the valuation hierarchy (meaning that their fair value was determined by reference to quoted prices for similar assets or liabilities or other observable inputs), with the remaining amounts categorized in level 3 (meaning that their fair value was determined by reference to inputs that are unobservable in the market and therefore require a greater degree of management judgment). Excluding the effect of master netting agreements, the fair value of level 3 assets at March 31, 2008 was $6.97 billion, or 8.5% of total assets carried at fair value, and the fair value of level 3 liabilities was $656 million, or 5% of total liabilities carried at fair value. The determination of fair value for securities categorized in level 2 or 3 involves significant judgment due to the complexity of factors contributing to the valuation, many of which are not readily observable in the market. In addition, we have historically placed a high level of reliance on information obtained from

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third-party sources to measure fair values. Third-party sources also use assumptions, judgments and estimates in determining securities values, and different third parties may provide different prices for securities. Moreover, depending upon, among other things, the measurement date of the security, the subsequent sale price of the security may be different from its recorded fair value. These differences may be significant especially if the security is sold during a period of illiquidity or market disruption or as part of a large block of securities under a forced transaction. See note 9, "Fair Value Measurements", to the consolidated financial statements included in our Quarterly Report on Form 10-Q for the quarter ended March 31, 2008, which is incorporated by reference into this prospectus supplement, for a more detailed discussion of the criteria used to categorize securities in level 1, 2 or 3 of the valuation hierarchy.

          As of March 31, 2008, in connection with management's measurements of fair value referenced above, there were $3.16 billion of pre-tax net unrealized losses associated with our investment securities portfolio. When the fair value of a security declines, management must assess whether that decline is "other-than-temporary". When the decline in fair value is deemed an "other-than-temporary" impairment, the amortized cost basis of the investment security is reduced to its then current fair value through a charge to earnings. The review of whether a decline in fair value is other-than-temporary considers numerous factors such as: adverse situations that might affect the ability to fully collect interest and principal; the credit quality and performance of any underlying collateral and guarantees; the length of time the amortized cost has exceeded the fair value and the severity of this impairment relative to the security's amortized cost basis; external credit ratings and current developments with respect to the security; management's intent and ability to hold the security until recovery in market value; management's assessment of current market conditions and future expectations; and current and expected future interest rates. Many of these factors involve significant judgment. If all or a significant portion of this unrealized loss were determined to be other-than-temporary impairment, we would recognize a material charge to earnings in the quarter during which such determination was made, our capital ratios would be adversely impacted and a rating agency might downgrade our credit rating or put us on credit watch. A downgrade or a significant reduction in our capital ratios might adversely impact our ability to access the capital markets or might increase our cost of capital.

          In our business activities, we assume liquidity and interest-rate risk in managing longer-term assets or asset pools for third parties that are funded on a short-term basis, or where the customers participating in these products may have a right to the return of cash or assets on limited notice. These business activities include, among others, the unconsolidated asset-backed commercial paper conduits administered by our Structured Products group, securities finance collateral pools and money market and other short-term investment funds.

          In the asset-backed commercial paper conduits, for example, pools of medium- and long-term financial instruments, principally mortgage- and other asset-backed securities, are financed through the issuance of short-term commercial paper. The conduits strive to maintain a positive margin between the rate of return on their longer-term assets and the short-term cost of funding. This mismatch in the maturity of the investment pools and funding creates risk if disruptions occur in the liquidity of the short-term debt or asset-backed securities markets, or if the cost of short-term borrowings exceeds the conduits' rate of return on their investment pools or purchased assets.

          In connection with the administration of the activities of the asset-backed commercial paper conduits, we provide contractual back-up liquidity to the conduits if they cannot meet their liquidity needs through the issuance of commercial paper. In the event that maturing commercial paper cannot be placed by the conduits, we are required by contract to, among other things, provide liquidity to the conduits by purchasing portfolio assets from them. During the first quarter of 2008, pursuant to these contractual obligations, we were required to purchase $850 million of conduit assets. The securities were purchased at prices determined in accordance with existing contractual terms of the liquidity asset purchase agreement, and which exceeded their fair value. Accordingly, the securities were written down

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to fair value through a $12 million reduction of processing fees and other revenue in our consolidated statement of income. These purchases were funded from our general liquidity, and the assets were recorded on our consolidated balance sheet. We also provide liquidity by purchasing commercial paper or providing other extensions of credit to the conduits. As of April 30, 2008, we held on our consolidated balance sheet an aggregate of approximately $1.18 billion of commercial paper issued by the conduits, compared to $292 million as of March 31, 2008 and $2 million as of December 31, 2007. Our contractual arrangements with the conduits also require that we purchase conduit portfolio assets under other circumstances, such as a downgrade of our credit rating.

          If circumstances change we may be required, under existing accounting standards, to consolidate some or all of the otherwise unconsolidated conduits onto our consolidated balance sheet. In the event State Street were to consolidate the conduits, there may be a significant charge reflecting the difference between the book value and the market value of each of the conduit's portfolios. For example, if changes in market conditions require us to update the assumptions in our expected loss model, we may be required to increase the amount of first-loss notes in order for the investors in the first-loss notes to continue to be considered the primary beneficiaries of the conduits. During the first quarter of 2008, some of the conduits issued additional first-loss notes totaling $20 million to third parties, increasing the total first-loss notes outstanding at March 31, 2008 to $52 million. In various circumstances, including if the conduits are not able to issue additional first-loss notes or take other actions, we may be determined to be the primary beneficiary of the conduits, and we would be required to consolidate the conduits' assets and liabilities onto our consolidated balance sheet. In addition, existing accounting standards may be changed or interpreted differently in the future in a manner that increases the risk of consolidation of the conduits.

          Consolidation, or the purchase of the assets of the conduits pursuant to the contractual agreements described above, could affect the size of our consolidated balance sheet and related funding requirements, our financial and regulatory capital ratios and, if the conduit assets include unrealized losses, could require us to recognize those losses. As of March 31, 2008, these unrealized losses amount to $1.49 billion after-tax. Because of our contractual agreements to purchase assets from the conduits under specified conditions, we are also exposed to the credit risks in the conduits' portfolios subject to first-loss coverage. Conditions in the financial markets that might warrant consolidation of the conduits or the purchase of assets may also require us to recognize other-than-temporary impairment in our investment portfolio. The Financial Accounting Standard Board is considering changes to accounting standards related to off-balance sheet vehicles such as the conduits, and industry-wide revisions are under discussion that could require us to consolidate all of the conduits we administer into our financial statements in the future, possibly as early as January 1, 2009.

          If consolidation of the conduits, purchase of the conduit assets pursuant to contractual arrangements or recognition of unrealized loss as other-than-temporary impairment were to occur, our capital ratios would be adversely affected. The degree of the adverse impact would depend upon many factors including our capital ratios at the time of such occurrence, the amount of loss realized and management actions, such as raising capital, that might mitigate the impact of a loss.

          We also manage other assets that are funded in the short-term markets and invested in longer-term markets, including securities finance collateral pools and money market and other short-term investment funds. These businesses involve risks inherent in an arbitrage of funding and investment; however, in these businesses, we primarily act as agent and do not have the direct principal risk. For example, if a collateral pool or a money market fund that we manage were to have unexpected liquidity demands from investors in the pool that exceeded available liquidity, the investment pool could be required to sell assets to meet those redemption requirements. During periods of disruption in the credit markets, it may be difficult to sell the assets held by these pools at a reasonable price. In those circumstances, the financial loss accrues to the pools' investors and not to us.

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          The credit risks inherent in these portfolios are attributable to the investors in the investment pools and not to State Street. These investment pools may have significant exposure to individual credits. The incurrence of substantial losses in these pools, particularly in money market funds, could result in significant harm to our reputation and significantly and adversely affect the prospects of our associated business units. In some circumstances, we may seek to mitigate that risk by compensating the investment pools for all or a portion of such losses even though we are not contractually obligated to do so; however, that would potentially result in the recognition of significant losses or a greater use of capital than we have available and could in certain extreme situations require us to consolidate the investment pools onto our consolidated balance sheet.

          SSgA manages certain accounts that have the benefit of contractual arrangements with third party financial institutions, which allow the accounts to issue and redeem units based upon the book value of the account's assets rather than their market value. The third-party financial institutions, known as "wrap providers", generally have an obligation to fund any shortfall in the account after all qualified participant withdrawals have been redeemed at a price based upon the assets' book value. As of April 30, 2008, these accounts had a total book value of $14.6 billion, of which $10.3 billion is subject to contractual wrap arrangements and $4.3 billion consists of cash and guaranteed investment contracts. Several financial institutions currently provide such contractual wrap arrangements. Securities representing 92.5% of the book value of the $10.3 billion wrapped portion of these accounts are rated "AA" or better as of April 30, 2008, and the average duration of the securities in the accounts was generally three years or less. Many of these accounts were significantly impacted by the volatility and lack of liquidity in the fixed-income securities markets beginning in the second half of 2007 and experienced a variance between market and book values greater than that experienced in more liquid markets. As contemplated when we established the reserve in connection with SSgA's active fixed-income strategies, we used $160 million of the reserve to decrease the difference between the market and book values of the wrapped portion of these accounts, and in part as a result of this action, the average market-to-book-value ratio of the wrapped portion of these accounts on January 31, 2008 increased to 96.77% from 93.43% on December 26, 2007.

          The volatility and illiquidity in the fixed-income securities markets during 2008 continue to impact the assets held by these accounts and have further reduced their market values. As of April 30, 2008, the average market-to-book-value ratio on the wrapped portion of these accounts was approximately 94.1%. This deficiency, or a further deterioration in the market-to-book-value ratio, could lead one or more wrap providers to discontinue their relationship with us. Factors that could lead to further deterioration in the market-to-book-value ratio, or the crediting rate earned by the accounts, include a decline in market value of securities held or of fixed-income securities generally due to illiquidity, interest-rate or credit risk or net cash outflows due to redemptions by participants in the accounts. A wrap provider could attempt to minimize its exposure to further deterioration in market value of the portfolio under its contract. It could do so by exercising its contractual right to require the account to be managed within more restrictive investment guidelines. This election is known as "immunization". Following such an election, investments made with additional cash contributions from participants are excluded from the wrap provider's contractual obligations. We also have the contractual right to elect to immunize all or a portion of these accounts at any time, including following receipt of notice of a wrap provider's election to terminate its agreement that benefit the accounts. The right of the participating investors to redeem their units at a price based on book value would not be affected by termination by a wrap provider or immunization. However, immunization of all or part of an account may adversely impact cash flows with respect to the account, potentially resulting in significant account redemptions. Moreover, our ability to continue to offer an attractive crediting rate on these accounts, our reputation as a manager of these types of products in the defined contribution market and the amount of fees that we recognize from this portion of our business, would be adversely impacted.

          One of our wrap providers has notified us of its election to terminate its relationship with us during the third quarter of 2008 as a result of its decision to exit the business of providing wrap

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contracts. We are seeking to replace this wrap provider, but there can be no assurance that we will be able to do so. There are a limited number of third-party financial institutions that currently offer these products, limiting the potential to find alternative wrap providers, and most accounts have investment guidelines requiring multiple wrap contracts. Moreover, one or more of our other wrap providers may seek to condition continuing to wrap our products on our taking action to further support the market value of the accounts' assets, although we are not contractually obligated to take such an action. If we support the market value of these accounts under any circumstances to mitigate the risks to our business, the cost to us could be material. Moreover, any action by us to support these accounts could result, depending on the nature and extent of such support, in the accounts being consolidated on our balance sheet for financial reporting purposes. If we were unable to replace one or more wrap providers that elect to terminate their arrangements with us, we may elect to immunize the portion of the accounts wrapped by the terminating wrap providers. Any action resulting in immunization of a part of an account could cause either the other wrap providers or us to elect immunization of the remainder of such account. In addition, a wrap provider may seek to eliminate or reduce its contractual obligations. Such an action could result in litigation with the defaulting wrap provider and the plans investing in the accounts. Any discontinuation of the contracts with our existing wrap providers, any inability to enter into new contracts with other wrap providers, any failure by a wrap provider to fund account shortfalls under its contract or any action by us or by a wrap provider to immunize all or a portion of the wrapped accounts would adversely affect our business.

          Investment, operational and other decisions and actions, often made to achieve scale and other benefits, are implemented over multiple investment pools as applicable, increasing the opportunity for losses, even small losses, to have a significant effect. To mitigate these risks to the investment pools, we seek to prudently manage the duration and credit exposure of the pools, to satisfy large liquidity demands by the in-kind delivery of securities held by the pools and to closely monitor liquidity demand from investors; however, market conditions or increased defaults could result in our inability to effectively manage those risks. To some degree, all of our investment management pools hold potential risks to our reputation and business prospects if the asset pools that we manage have higher than anticipated redemption or other liquidity requirements and the pools incur losses to meet such demands.

          Other parts of our business where we primarily act as agent, such as other investment management activities of SSgA and certain of our broker/dealer-related businesses, do not currently have significant liquidity requirements; however, as we develop new products in response to customer demand and to remain competitive in a dynamic marketplace, we could take on more principal risk in these businesses. Any increase in the extent to which these or other businesses assume principal positions would increase the risks associated with our liquidity management strategy.

          The disruption in the global fixed-income securities markets beginning in the third quarter of 2007 has had a substantially greater impact upon liquidity and valuations in those markets than has historically been experienced. Because demand from investors for fixed-income products has markedly decreased and dealers have been less prepared to take principal exposures, funding sources, such as the commercial paper markets for conduits, have been less reliable and more expensive. At the same time, the ability of the markets to absorb the sale of certain types of fixed-income securities has been substantially impaired. These market conditions have made the management of our own and our customers' liquidity significantly more challenging. As discussed above, the risks to State Street inherent in its management of liquidity are significant, and a further deterioration in the credit markets could adversely affect our consolidated financial position, including our regulatory capital ratios, and could adversely affect our results of operations and our business prospects in the future.

Reputational Risk

          Our relationship with many of our customers is predicated upon our reputation as a fiduciary and a service provider that adheres to the highest standards of ethics, service quality and regulatory

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compliance. Adverse publicity, regulatory actions, litigation, operational failures, the failure to meet client expectations and other issues could materially and adversely affect our reputation and our ability to retain and attract customers. Preserving and enhancing our reputation depends not only on maintaining systems and procedures that address known risks and regulatory requirements, but also our ability to identify and mitigate additional risks that arise due to changes in our businesses and the marketplaces in which we operate, the regulatory environment, and customer expectations. If any of these developments, including our recently announced customer concerns related to certain SSgA active fixed-income strategies, has a material effect on our reputation, our business will suffer.

Credit Risk

          Our focus on large institutional investors and their businesses requires that we assume credit and counterparty risk, both on-and off-balance sheet, in a variety of forms. We may experience significant intra- and inter-day credit exposure through settlement- related extensions of credit. From time to time, we may assume concentrated credit risk at the individual obligor, counterparty, guarantor, industry and/or country level, thereby potentially exposing us to a single market or political event or a correlated set of events. The credit quality of our on- and off-balance sheet exposures may be affected by many factors, such as economic and business conditions or deterioration in the financial condition of an individual counterparty, group of counterparties or asset classes. If a significant economic downturn occurs in either a country or a region, or we experience the failure of a significant individual counterparty, we could incur financial losses that could adversely affect our earnings.

Financial Markets Risk

          As asset values in worldwide financial markets increase or decrease, our opportunities to invest in and service financial assets change. Given that a portion of our fee revenue is based on the value of assets under custody and management, fluctuations in the valuation of worldwide securities markets will affect revenue. Many of the costs of providing our services are relatively fixed; therefore, a decline in revenue could have a disproportionate effect on our earnings. In addition, if investment performance in our asset management business fails to meet either benchmarks or the performance of our competitors, we could experience a decline in assets under management and a reduction in the fees that we earn, irrespective of economic or market conditions.

          We have increased the portion of our management fee revenue that is generated from enhanced index and actively managed products, with respect to which we generally receive higher fees compared to passive products. We may not be able to continue to increase this segment of our business at the same rate that we have achieved in the past few years. The amount of assets in active fixed-income strategies, for example, has been adversely impacted since 2007. In addition, with respect to certain of our enhanced index and actively managed products, we have entered into performance fee arrangements, where the management fee revenue we earn is based on the performance of managed funds against specified benchmarks. The reliance on performance fees increases the potential volatility of our management fee revenue.

          Financial markets trading businesses, as well as our asset and liability management activities, are also subject to market risks. Adverse movements in levels and volatilities of financial markets could cause losses that may affect our consolidated results of operations and financial condition. In addition, changes in investor and rating agency perceptions regarding certain asset classes or structures can also affect volatility, liquidity and market prices, which, in turn, can lead to losses. The degree of volatility in foreign exchange rates can affect our foreign exchange trading revenue. In general, we benefit from currency volatility, although it can increase risk. Foreign exchange revenue, all other things being equal, is likely to decrease during times of decreased currency volatility. In addition, as our business grows globally, our exposure to changes in foreign currency exchange rates could affect our levels of revenue, expense and earnings, as well as the value of our investment in our non-U.S. operations.

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Interest-Rate Risk

          State Street's financial performance could be unfavorably affected by changes in interest rates as they impact our asset and liability management activities. The levels of global market interest rates, the shape of these yield curves (changes in the relationship between short- and long-term interest rates), the direction and speed of interest rate changes, and the asset and liability spreads relative to the currency and geographic mix of our interest-earning assets and interest-bearing liabilities, affect our net interest revenue. Our ability to anticipate these changes and/or to hedge the related exposures on and off our consolidated balance sheet can significantly influence the success of our asset and liability management activities and the resulting level of our net interest revenue. The impact of changes in interest rates will depend on the relative durations of assets and liabilities in accordance with their relevant currencies. In general, sustained lower interest rates, a flat or inverted yield curve and narrow interest-rate spreads have a constraining effect on our net interest revenue.

Operational Risk

          Operational risk is inherent in all of State Street's activities. Our customers have a broad array of complex and specialized servicing, confidentiality and fiduciary requirements. We have established policies, procedures and systems designed to comply with these regulatory and operational risk requirements. We also face the potential for loss resulting from inadequate or failed internal processes, employee supervisory or monitoring mechanisms, or other systems or controls, and from external events, which could materially affect our future results of operations. We may also be subject to disruptions from events that are wholly or partially beyond our control, which could cause delays or disruptions to operational functions, including information processing and financial market settlement functions. In addition, our customers, vendors and counterparties could suffer from such events. Should these events affect us, or the customers, vendors or counterparties with which we conduct business, our results of operations could be negatively affected.

          Our success depends, in large part, on our ability to attract and retain key people. Competition for the best people in most activities in which we engage can be intense, and we may not be able to hire people or retain them. The unexpected loss of services of one or more of our key personnel could have a material adverse impact on our business because of their skills, their knowledge of our markets, their years of industry experience, and, in some cases, the difficulty of promptly finding qualified replacement personnel. Similarly, the loss of key staff, either individually or as a group, can adversely impact customer perception of our ability to continue to manage certain types of investment management mandates. In some of our businesses, we have experienced significant employee turnover, which increases costs, requires additional training and increases the potential for operational risks.

          We enter into long-term fixed-price contracts to provide middle office or investment manager and hedge fund manager operations outsourcing services to customers, services related but not limited to certain trading activities, cash reporting, settlement and reconciliation activities, collateral management and information technology development. These long-term contracts require considerable up-front investment by us, including technology and conversion costs, and carry the risk that pricing for the products and services we provide might not prove adequate to generate expected operating margins over the term of the contracts. Profitability of these contracts is largely a function of our ability to accurately calculate pricing for our services and our ability to control our costs and maintain the relationship with the customer for an adequate period of time to recover our up-front investment. Performance risk exists in each contract, given our dependence on successful conversion and implementation onto our own operating platforms of the service activities provided. In addition, our failure to meet specified service levels may adversely affect our revenue from such arrangements, or permit early termination of the contracts by the customer.

          We actively strive to achieve significant cost savings by shifting certain business processes to lower-cost geographic locations, while continuing to maintain service quality, control and effective

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management of risks within these business operations. This transition to a true "shared services" operational model focuses on certain core service offerings, including middle- and back-office reconciliations, securities processing and transfer agency activities. We have employed various structural arrangements to achieve these goals, including forming joint ventures and wholly-owned subsidiaries and establishing operations in lower cost areas, such as Eastern Europe, India and China, and outsourcing to vendors in various jurisdictions. The increased elements of risk that arise from conducting certain operating processes in some jurisdictions could lead to an increase in reputational risk. During periods of transition, greater operational risk and client concern exists regarding the continuity of a high level of service delivery. The extent and pace at which we are able to move functions to lower-cost locations may also be impacted by regulatory and customer acceptance issues. Such relocation of functions also entails costs, such as technology and real estate expenses, that partially offset the financial benefits of the lower-cost locations.

          Our businesses depend on an information technology infrastructure to record and process a large volume of increasingly complex transactions, in many currencies, on a daily basis, across numerous and diverse markets. Any interruptions, delays and/or breakdowns of this infrastructure can result in significant costs and reputational damage. As a result, we continue to invest significantly in this infrastructure.

          Our businesses and our relationship with customers are also dependent upon our ability to maintain the confidentiality of our and our customers' trade secrets and confidential information (including personal data about our employees, our customers and our customers' customers). While we undertake significant efforts to maintain and protect confidential information from theft, loss or other misappropriation, unauthorized access to such information can occur. In this regard, on May 29, 2008, we announced that we are sending precautionary notifications to employees and certain customers of the former Investors Financial that computer equipment containing certain personal data was stolen from the facility of an Investors Financial vendor. Any theft, loss or other misappropriation of confidential information could have a material adverse impact on our competitive positions, our relationships with our customers and our reputation and could subject us to regulatory inquiries and enforcement, civil litigation and possible financial liability or costs.

          To the extent that we are not able to protect our intellectual property through patents or other means, we are also exposed to the risk that employees with knowledge of such intellectual property may leave and seek to exploit our intellectual property for their own or others' advantage.

Litigation Risks

          From time to time, our customers may make claims and take legal action relating to our performance of fiduciary or contractual responsibilities. If such claims and legal actions are not resolved in a manner favorable to us, such claims may result in financial liability to State Street and/or adversely affect the market perception of us and our products and services, and could impact customer demand for our products and services. We record balance sheet reserves for probable loss contingencies, including litigation and operational losses. However, we cannot always accurately estimate our ultimate exposure. As a result, any reserves we establish to cover any settlements, judgments or operational losses may not be sufficient to cover our actual financial exposure. Any underestimation or overestimation could have a material impact on our consolidated financial condition or results of operations.

          In connection with certain of SSgA's active fixed-income strategies, we established a reserve to cover legal exposure and related costs in connection with such strategies as of December 31, 2007. Among other things, the portfolio managers for certain actively managed fixed-income strategies materially increased the exposure of these strategies to securities collateralized by sub-prime mortgages and shifted the weighting of these portfolios to more highly rated sub-prime instruments. During the third quarter of 2007, as the liquidity and valuations of these securities, including the more highly rated

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instruments, came under increased pressure, the performance of these strategies was adversely affected, in some cases significantly. The underperformance, which was greater than that typically associated with fixed-income funds, also caused a number of our customers to question whether the execution of these strategies was consistent with their investment intent. This has resulted in several civil suits, including putative class action claims. These lawsuits allege, among other things, that we failed to comply with our standard of care in managing these active funds as a fiduciary under ERISA. We have also received and are in the process of responding to inquiries or subpoenas from federal and state regulatory authorities regarding SSgA's active fixed-income strategies. Given our desire to fully respond to customer concerns, following the end of the third quarter of 2007, State Street undertook a further review of all the actively managed fixed-income strategies at SSgA that were exposed to sub-prime investments. Based on our review and ongoing discussions with customers who were invested in these strategies, we established the reserve to address our estimated legal exposure.

          The reserve was established based upon our best judgment as to legal exposures and related costs associated with certain actively managed fixed-income investment strategies. As of March 31, 2008, we had made settlement and related payments totaling approximately $275 million, including amounts expended to support certain accounts managed by SSgA that benefit from contractual arrangements with "wrap providers". The amount of the reserve is based on certain assumptions. While we believe the reserve represents a reasonable estimate of our legal exposure and other costs associated with these issues, we do not believe that it is feasible to predict or determine the amount of such exposure with certainty. As such, it is possible that we have overestimated or underestimated our exposure. If the amount of our actual exposure is materially different from our reserve, there would be a material impact on our consolidated financial condition and results of operations.

          To determine whether the issues that arose within the active fixed-income area are limited to SSgA's active fixed-income strategies, we are conducting, with the assistance of third-party consultants, a systematic review of the operational, risk and compliance infrastructure, procedures and resources across SSgA's entire product line. While this review is ongoing, the conclusions or recommendations that have been made to date have not identified any material legal or regulatory exposures; however, there can be no assurance at this time as to the ultimate conclusions of such review.

Regulatory/Legal/Accounting/Tax Risk

          Most of our businesses are subject to extensive regulation, and many of the customers to which we provide services are themselves subject to a broad range of regulatory requirements. These regulations may affect the manner and terms of delivery of our services. As a financial institution with substantial international operations, we are subject to extensive regulatory and supervisory oversight, both in the U.S. and overseas in connection with our global operations. Our businesses are subject to stringent regulation and examination by U.S. federal and state governmental and regulatory agencies, including the Federal Reserve, the SEC and the Massachusetts Commissioner of Banks, and self-regulatory organizations (including securities exchanges), and by non-U.S. governmental and regulatory agencies and self-regulatory organizations. The regulations affect, among other things, the scope of our activities and customer services, our capital structure and our ability to fund the operations of our subsidiaries, our lending practices, our dividend policy and the manner in which we market our services. Evolving regulations, such as the new Basel II regulatory capital framework and anti-money laundering regulations, can require significant effort on our part to ensure compliance. New or modified regulations and related regulatory guidance may have unforeseen or unintended adverse effects on the financial services industry.

          If we do not comply with governmental regulations, we may be subject to fines, penalties or material restrictions on our businesses in the jurisdiction where the violation occurred, which may adversely affect our business operations and, in turn, our financial results. Similarly, many of our customers are subject to significant regulatory requirements, and retain our services in order for us to assist them in complying with those legal requirements. Changes in these regulations can significantly

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affect the services that we are asked to provide, as well as our costs. If we cause customers to fail to comply with these regulatory requirements, we may be liable to them for losses and expenses that they incur. In addition, adverse publicity and damage to our reputation arising from the failure or perceived failure to comply with legal, regulatory or contractual requirements could affect our ability to attract and retain customers or to maintain access to capital markets, or could result in enforcement actions, fines, penalties and lawsuits. In recent years, regulatory oversight and enforcement have increased substantially, imposing additional costs and increasing the potential risks associated with our operations. If this regulatory trend continues, it could adversely affect our operations and, in turn, our financial results.

          In the ordinary course of our business, we are involved from time to time in civil litigation or arbitration, including actions arising out of our contractual, fiduciary or employment relationships. In certain of these actions, claims for substantial monetary damages may be asserted against us. In the ordinary course of our business, we are also subject to various regulatory, governmental and law enforcement inquiries, investigations and subpoenas. These may be directed generally to participants in the businesses in which we are involved or may be specifically directed at us. In regulatory enforcement matters, claims for disgorgement, the imposition of penalties and the imposition of other remedial sanctions are possible. Among other inquiries, investigations and subpoenas, we have received federal and state regulatory inquiries or subpoenas relating to SSgA's active fixed-income strategies as to which we established a reserve in the fourth quarter of 2007. There can be no assurance as to the outcome of the inquiries with regard to the SSgA's fixed-income strategies or any other matter. Additional legal actions or regulatory matters may be initiated from time to time in the future.

          In view of the inherent difficulty of predicting the outcome of such legal actions and regulatory matters, we can not provide assurance as to the outcome of any pending matter or, if determined adversely to us, the costs associated with any such matter, particularly where the claimant seeks very large or indeterminate damages or where the matter presents novel legal theories, involves a large number of parties or is at a preliminary stage. Based upon the information currently available to us, we do not believe that any pending legal actions or regulatory matters will have a material adverse effect on our consolidated financial condition or results of operations. However, the resolution of certain pending legal actions or regulatory matters, if unfavorable, could have a material adverse effect on our consolidated results of operations for any particular quarter, depending on the magnitude of the loss or liability relative to our results for that quarter.

          New accounting standards, or changes in the interpretation of existing accounting standards, by the Financial Accounting Standards Board or the SEC, can potentially affect our consolidated financial condition and results of operations. These changes are very difficult to predict, and can materially impact how we record and report our consolidated financial condition and results of operations and other financial information. In some cases, we could be required to apply a new or revised standard retroactively, resulting in the revised treatment of certain transactions or activities, and, in some cases, the restatement of prior period financial statements.

          Our businesses can be affected by new tax legislation or the interpretation of existing tax laws worldwide. Changes in tax laws may affect our business directly or indirectly through their impact on the financial markets. In the normal course of business, we are subject to reviews by U.S. and non-U.S. tax authorities. These reviews may result in adjustments to the timing or amount of taxes due and the allocation of taxable income among tax jurisdictions. These adjustments could affect the attainment of our financial goals.

          Prior to 2004, we entered into certain leveraged leases, known as sale-in, lease-out, or SILO, transactions. In accordance with Statement of Financial Accounting Standards, or SFAS, No. 13, Accounting for Leases, we recorded income and deferred tax liabilities with respect to the SILO transactions based on projected pre-tax and tax cash flows. The Internal Revenue Service, or IRS, has proposed disallowing tax deductions arising from those transactions, and we have been engaged in

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settlement discussions. In connection with these discussions we have revised our projections of the timing of tax cash flows and we have reflected those revisions in our leveraged lease accounting under SFAS No. 13. We have also substantially reserved for tax-related interest expense that may be incurred upon resolution of this matter. On May 28, 2008, in a case involving a SILO transaction of another taxpayer, a federal district court upheld the IRS' tax position. We do not yet know what effect, if any, such decision may have on our settlement discussions with the IRS or on our evaluation of the potential exposure with respect to the SILO transactions. If we were to further revise our projection of the timing of tax cash flows from the leases, SFAS No. 13 would require us to again recalculate the rate of return and the timing of the recognition of income from the leases from inception. The effect of the SFAS No. 13 recalculation would be to reschedule the recognition of previously-recognized income to future periods; that is, the charge we would record to income during the period of revision would be recovered over the remaining lives of the leases. In addition to the SFAS No. 13 recalculation, we would increase our reserve for tax-related interest expense, which would be recorded as an increase to income tax expense.

Risk Management

          A comprehensive and well-integrated risk management function linked to our strategy and capital is essential to the financial and operational success of our global business activities. We seek to monitor and manage risk on a corporate basis and within specific business units. The types of risk that we monitor and seek to manage include, but are not limited to, operational risk, interest-rate risk, trading risk, fiduciary risk, legal and compliance risk, liquidity risk and credit risk. We have adopted various policies, procedures and systems to monitor and manage risk. There can be no assurance that those policies, procedures or systems are adequate to identify and mitigate all risks inherent in our various business. In addition, our businesses and the markets in which we operate are continuously evolving. We may fail to fully understand the implications of changes in our business or the financial markets and fail to adequately or timely enhance our risk framework to address those changes. If our risk framework is ineffective, either because it fails to keep pace with changes in the financial markets or our business or for other reasons, we could incur losses.

          We also measure our material risks. Our measurement methodologies rely upon many assumptions and historical analyses and correlations. There can be no assurance that those assumptions will be correct or that the historical correlations will continue to be relevant. Consequently the measurements that we make for regulatory and economic capital may not adequately capture or express the true risk profiles of our businesses. Additionally, as businesses and markets evolve, our measurements may not accurately reflect those changes. While our risk measures may indicate sufficient capitalization, we may in fact have inadequate capital to conduct our businesses.


Risks Related to Our Common Stock

Stock Price Volatility Risk

          The price of our common stock on the New York Stock Exchange constantly changes. We expect that the market price of our common stock will continue to fluctuate. Our stock price may fluctuate as a result of a variety of factors, many of which are beyond our control. These factors include:

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          In addition, in recent years, the stock market in general has experienced extreme price and volume fluctuations. This volatility has had a significant effect on the market price of securities issued by many companies, including for reasons unrelated to their operating performance. These broad market fluctuations may adversely affect our stock price, notwithstanding our operating results.

Dilution Risk

          Except as described under "Underwriting", we are not restricted from issuing additional common stock, including any securities that are convertible into or exchangeable for, or that represent the right to receive, common stock. The market price of our common stock could decline as a result of sales of shares of our common stock made after this offering or the perception that such sales could occur.

          Our board of directors is authorized to issue additional classes or series of preferred stock without any action on the part of the stockholders. The board of directors also has the power, without stockholder approval, to set the terms of any such classes or series of preferred stock that may be issued, including voting rights, dividend rights, and preferences over our common stock with respect to dividends or upon our dissolution, winding-up and liquidation and other terms. If we issue preferred stock in the future that has a preference over our common stock with respect to the payment of dividends or upon our liquidation, dissolution, or winding up, or if we issue preferred stock with voting rights that dilute the voting power of our common stock, the rights of holders of our common stock or the market price of our common stock could be adversely affected.

Restrictions on Ownership

          The Bank Holding Company Act requires any "bank holding company", as defined in the Bank Holding Company Act, to obtain the approval of the Federal Reserve Board prior to the acquisition of 5% or more of our common stock. Any person, other than a bank holding company, is required to obtain prior approval of the Federal Reserve Board to acquire 10% or more of our common stock under the Change in Bank Control Act. Any holder of 25% or more of our common stock, or a holder of 5% or more if such holder otherwise exercises a "controlling influence" over us, is subject to regulation as a bank holding company under the Bank Holding Company Act. Chapter 167A of the General Laws of Massachusetts requires any "bank holding company", as defined in Chapter 167A, to obtain prior approval of the board of bank incorporation before (i) acquiring 5% or more of our common stock, (ii) acquiring all or substantially all of our assets or (iii) merging or consolidating with us.

Dividend Risk

          Holders of our common stock are only entitled to receive such dividends as our board of directors may declare out of funds legally available for such payments. We are not required to declare cash dividends on or common stock. Future dividend payments will depend upon our level of earnings, financial requirements and other relevant factors, including dividend restrictions contained in our debt instruments, if any. In the future, we may not continue to increase the quarterly common stock dividend or may reduce or eliminate our common stock dividend. These actions could adversely affect the market price of our common stock.

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USE OF PROCEEDS

          We expect to receive net proceeds from this offering of approximately $2.4 billion (or approximately $2.8 billion if the underwriters exercise in full their option to purchase additional shares), after deducting estimated expenses and underwriting discounts and commissions.

          We intend to use the net proceeds for general corporate purposes, which include working capital, capital expenditures, investments in or loans to our subsidiaries, refinancing of debt, including outstanding commercial paper and other short-term indebtedness, if any, and satisfaction of other obligations. The precise amounts and timing of the application of proceeds will depend on the funding requirements of State Street Corporation and its subsidiaries, including State Street Bank.

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PRICE RANGE OF COMMON STOCK AND DIVIDENDS

          Our common stock trades on the New York Stock Exchange under the symbol "STT". As of May 30, 2008, there were 390,960,437 shares of our common stock issued and outstanding. As of May 30, 2008, there were approximately 5,041 stockholders of record. The following table provides the high and low sales price per share during the periods indicated, as reported on the New York Stock Exchange, and dividends declared per share of our common stock during such periods.

Period
   High
   Low
   Dividends
2006:                  
  First Quarter   $ 63.73   $ 55.42   $ 0.19
  Second Quarter     66.47     56.27     0.20
  Third Quarter     64.35     54.39     0.20
  Fourth Quarter     68.56     60.96     0.21
2007:                  
  First Quarter   $ 72.82   $ 61.70   $ 0.21
  Second Quarter     70.58     64.21     0.22
  Third Quarter     73.76     59.13     0.22
  Fourth Quarter     82.53     66.79     0.23
2008:                  
  First Quarter   $ 86.55     69.75   $ 0.23
  Second Quarter (through May 30, 2008)     85.31     65.01     —

          We have increased our quarterly dividend twice each year since 1978. We intend to continue the payment of dividends, although future dividend payments will depend upon our level of earnings, financial requirements and other relevant factors, including dividend restrictions contained in our debt instruments.

          The last reported sales price per share of our common stock on May 30, 2008, as reported by the New York Stock Exchange, was $72.02.

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STATE STREET CAPITALIZATION

          The following table sets forth the consolidated capitalization of State Street at March 31, 2008 and as adjusted to give effect to the issuance of our common stock in this offering. You should read this table in conjunction with the consolidated financial statements and related notes thereto in State Street's Quarterly Report on Form 10-Q for the quarter ended March 31, 2008, which is incorporated by reference into this prospectus supplement.

 
   March 31, 2008(1)
 
   (Dollars in millions)
Long-Term Debt      
Statutory business trusts:      
  8.250% fixed-to-floating-rate normal automatic preferred enhanced capital securities   $ 500
  Floating-rate subordinated notes due to State Street Capital Trust IV in 2067     800
  Floating-rate subordinated notes due to State Street Capital Trust I in 2028     155
  9.77% subordinated notes due to Investors Capital Trust I in 2027     25

Parent company and non-bank subsidiary issuances:
 
 
 
  Long-term capital lease     482
  5.375% notes due 2017     450
  7.65% subordinated notes due 2010     312
  Floating-rate notes due 2012     250
  7.35% notes due 2026     150
  9.50% mortgage note due 2009     3

State Street Bank issuances:
 
 
 
  5.25% subordinated notes due 2018     436
  5.30% subordinated notes due 2016     399
  Floating-rate subordinated notes due 2015     200
   
Total long-term debt   $ 4,162
   
 
 
   As
Reported
   As
Adjusted
Shareholders' equity            
Preferred stock, no par: authorized 3,500,000 shares; issued none            
Common stock, $1 par: authorized 750,000,000 shares; issued 398,366,000 and                   shares as reported and as adjusted, respectively   $ 398   $  
Surplus     4,455      
Retained earnings     8,185      
Accumulated other comprehensive loss     (1,658 )    
Treasury stock, at cost (8,048,000 shares)     (574 )    
   
 
Total shareholders' equity   $ 10,806   $  
   
 
(1)
Information for the quarter ended March 31, 2008 is unaudited.

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CERTAIN U.S. FEDERAL TAX CONSEQUENCES TO NON-U.S. HOLDERS

          The following is a general discussion of the material U.S. federal income and estate tax considerations applicable to non-U.S. holders with respect to their purchase, ownership and disposition of shares of our common stock. This discussion is for general information only and is not tax advice. Accordingly, all prospective non-U.S. holders of our common stock should consult their own tax advisors with respect to the U.S. federal, state, local and non-U.S. tax consequences of the purchase, ownership and disposition of our common stock. In general, a non-U.S. holder means a beneficial owner of our common stock who is not for U.S. federal income tax purposes:

          This discussion is based on current provisions of the U.S. Internal Revenue Code of 1986, as amended, existing and proposed U.S. Treasury Regulations promulgated thereunder, current administrative rulings and judicial decisions, in effect as of the date of this prospectus supplement, all of which are subject to change or to differing interpretation, possibly with retroactive effect. Any change to the foregoing authorities could alter the U.S. federal income and estate tax consequences to non-U.S. holders described in this prospectus supplement. We assume in this discussion that a non-U.S. holder holds shares of our common stock as a capital asset (generally property held for investment).

          This discussion does not address all aspects of U.S. federal income and estate taxation that may be relevant to a particular non-U.S. holder in light of that non-U.S. holder's individual circumstances nor does it address any U.S. federal gift or alternative minimum tax consequences or state, local or non-U.S. tax consequences of the purchase, ownership and disposition of our common stock. This discussion also does not consider any specific facts or circumstances that may apply to a non-U.S. holder and does not address the special tax rules applicable to particular non-U.S. holders, such as:

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          If a partnership (or other entity treated as a partnership for U.S. federal income tax purposes) holds shares of our common stock, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. A partner and the partnership holding shares of our common stock should consult his, her or its tax advisors regarding the tax considerations of acquiring, holding and disposing of shares of our common stock.

          We cannot provide any assurance that the Internal Revenue Service, or the IRS, will not challenge one or more of the tax consequences described herein, and we have not obtained, nor do we intend to obtain, an opinion of counsel with respect to the U.S. federal income or estate tax consequences to a non-U.S. holder of the purchase, ownership, or disposition of our common stock. We urge prospective investors to consult with their own tax advisors regarding the U.S. federal, state, local and non-U.S. income and other tax considerations of acquiring, holding and disposing of shares of our common stock.

Distributions on Our Common Stock

          Distributions on our common stock generally will constitute dividends for U.S. federal income tax purposes to the extent paid from our current or accumulated earnings and profits, as determined under U.S. federal income tax principles. If a distribution exceeds our current and accumulated earnings and profits, the excess will be treated as a tax-free return of the non-U.S. holder's investment, up to such non-U.S. holder's tax basis in our common stock and thereafter as capital gain, subject to the tax treatment described below in "Gain on Sale, Exchange or Other Taxable Disposition of Our Common Stock".

          Dividends paid to a non-U.S. holder in respect of our common stock generally will be subject to U.S. federal withholding tax at a 30% rate, or such lower rate as may be specified by an applicable tax treaty. In order to claim the benefits of an applicable tax treaty, a non-U.S. holder will be required to satisfy applicable certification (for example, IRS Form W-8BEN or other applicable form) and other requirements prior to the distribution date. Non-U.S. holders eligible for a reduced rate of U.S. federal withholding tax under an applicable tax treaty may obtain a refund or credit of any amounts withheld in excess of that rate by filing an appropriate claim with the IRS. Non-U.S. holders should consult their own tax advisors regarding their entitlement to benefits under an applicable tax treaty and the requirements for claiming any such benefits.

          Dividends paid to a non-U.S. holder that are effectively connected with its conduct of a trade or business within the United States (and, if required by an applicable tax treaty, are attributable to a permanent establishment or fixed base maintained by the non-U.S. holder in the United States) generally are exempt from the 30% U.S. federal withholding tax. Instead, the non-U.S. holder generally will be subject to U.S. federal income tax in respect of the dividend on a net income basis and at the graduated U.S. federal income tax rates applicable to U.S. persons. Non-U.S. holders will be required to comply with certification (for example, IRS Form W-8ECI or applicable successor form) and other requirements prior to the distribution date in order for effectively connected income to be exempt from the 30% U.S. federal withholding tax. A corporate non-U.S. holder also may be subject to an additional "branch profits tax" at a 30% rate (or such lower rate as may be specified by an applicable tax treaty) with respect to any effectively connected dividends, subject to certain adjustments.

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Gain on Sale, Exchange or Other Taxable Disposition of Our Common Stock

          In general, a non-U.S. holder will not be subject to any U.S. federal income tax or withholding tax on any gain realized upon such holder's sale, exchange or other taxable disposition of shares of our common stock unless:


U.S. Federal Estate Tax

          Shares of our common stock owned or treated as owned at the time of death by an individual who is not a citizen or resident of the United States, as specifically defined for U.S. federal estate tax purposes, will be considered U.S. situs assets and will be included in such individual's gross estate for U.S. federal estate tax purposes. Such shares, therefore, may be subject to U.S. federal estate tax, unless an applicable tax treaty provides otherwise.

Backup Withholding and Information Reporting

          We must report annually to the IRS and to each non-U.S. holder the gross amount of the distributions on our common stock paid to such holder and the tax withheld, if any, with respect to such distributions. Copies of information returns may be made available to the tax authorities of the country in which the non-U.S. holder resides or is incorporated under the provisions of a specific treaty or agreement. In general, a non-U.S. holder will not be subject to backup withholding at the applicable rate, currently 28%, with respect to dividends on our common stock if the holder provides to us or our paying agent an appropriate certification of non-U.S. status (i.e., IRS Form W-8BEN or other

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applicable IRS Form W-8) and neither we nor our paying agent has actual knowledge (or reason to know) the holder is a U.S. person.

          Information reporting and, depending on the circumstances, backup withholding will apply to the payment of the proceeds from a disposition of our common stock that is effected within the United States or effected outside the United States through certain U.S.-related financial intermediaries, unless the non-U.S. holder appropriately certifies its non-U.S. status, and the payor does not have actual knowledge or reason to know that the beneficial owner is a U.S. person, or the non-U.S. holder otherwise establishes an exemption.

          Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules from a payment to a non-U.S. holder can be refunded or credited against the non-U.S. holder's U.S. federal income tax liability, if any, provided that an appropriate claim is timely filed with the IRS. Non-U.S. holders should consult their tax advisors regarding the application of information reporting and backup withholding in their particular situations, the availability of an exemption therefrom, and the procedure for obtaining an exemption, if applicable.

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CERTAIN ERISA CONSIDERATIONS

          Each person considering the use of plan assets of a pension, profit-sharing or other employee benefit plan, individual retirement account, Keogh plan or other retirement plan, account or arrangement, or a plan, to acquire or hold our common stock should consider whether an investment in our common stock would be consistent with the documents and instruments governing the plan, and whether the investment would involve a prohibited transaction under Section 406 of the Employee Retirement Income Security Act of 1974, as amended, or ERISA, or Section 4975 of the Internal Revenue Code of 1986, as amended, or the Code.

          Section 406 of ERISA and Section 4975 of the Code prohibit plans subject to Title I of ERISA and/or Section 4975 of the Code including entities such as collective investment funds, partnerships and separate accounts or insurance company pooled separate accounts or insurance company general accounts whose underlying assets include the assets of such plans, which we refer to collectively as plans, from engaging in certain transactions involving plan assets with persons who are parties in interest under ERISA or disqualified persons under the Code with respect to the plan. A violation of these prohibited transaction rules may result in civil penalties or other liabilities under ERISA and/or an excise tax under Section 4975 of the Code for those persons, unless exemptive relief is available under an applicable statutory, regulatory or administrative exemption. Certain plans including those that are governmental plans (as defined in Section 3(32) of ERISA), certain church plans (as defined in Section 3(33) of ERISA) and foreign plans (as described in Section 4(b)(4) of ERISA) are not subject to the requirements of ERISA or Section 4975 of the Code but may be subject to similar provisions under applicable federal, state, local, foreign or other regulations, rules or laws, which we refer to as similar laws.

          The acquisition or holding of our common stock by a plan with respect to which we or certain of our affiliates is or becomes a party in interest may constitute or result in prohibited transactions under ERISA or Section 4975 of the Code, unless our common stock is acquired or held pursuant to and in accordance with an applicable exemption.

          Accordingly, our common stock may not be purchased or held by any plan or any person investing plan assets of any plan, unless the purchase or holding is eligible for the exemptive relief available under a Prohibited Transaction Class Exemption, or PTCE, such as PTCE 96-23, PTCE 95-60, PTCE 91-38, PTCE 90-1 or PTCE 84-14 issued by the U.S. Department of Labor or the purchase and holding of our common stock is not prohibited on some other basis, such as the exemption under Section 408(b)(17) of ERISA and Section 4975(d)(20) of the Code, for certain transactions with non-fiduciary service providers for transactions that are for adequate consideration. Each purchaser or holder of our common stock or any interest therein, and each person making the decision to purchase or hold our common stock on behalf of any such purchaser or holder will be deemed to have represented and warranted in both its individual capacity and its representative capacity (if any), that on each day from the date on which the purchaser or holder acquires its interest in our common stock to the date on which the purchaser disposes of its interest in our common stock, that such purchaser and holder, by its purchase or holding of our common stock or any interest therein that:

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          Each purchaser and holder of our common stock or any interest therein on behalf of any governmental plan will be deemed to have represented and warranted by its purchase or holding of our common stock or any interest therein that such purchase and holding does not violate any applicable similar laws or rules.

          Due to the complexity of these rules and the penalties that may be imposed upon persons involved in non-exempt prohibited transactions, it is important that fiduciaries or other persons considering purchasing our common stock on behalf of or with "plan assets" of any plan or plan asset entity consult with their counsel regarding the availability of exemptive relief under any of the PTCEs listed above or any other applicable exemption, or the potential consequences of any purchase or holding under similar laws, as applicable.

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UNDERWRITING

          State Street and the underwriters named below have entered into an underwriting agreement with respect to the shares being offered. Subject to certain conditions, each underwriter has severally agreed to purchase the number of shares indicated in the following table. Goldman, Sachs & Co. is the representative of the underwriters.

Underwriters
   Number of Shares
Goldman, Sachs & Co.     
Morgan Stanley & Co. Incorporated    
Credit Suisse Securities (USA) LLC    
Lehman Brothers Inc.     
UBS Securities LLC    
   
Total    
   

          The underwriters are committed to take and pay for all of the shares being offered, if any are taken, other than the shares covered by the option described below unless and until this option is exercised.

          If the underwriters sell more shares than the total number set forth in the table above, the underwriters have an option to buy up to an additional            shares from State Street. They may exercise that option for 30 days. If any shares are purchased pursuant to this option, the underwriters will severally purchase shares in approximately the same proportion as set forth in the table above.

          The following table shows the per share and total underwriting discounts and commissions to be paid to the underwriters by State Street. Such amounts are shown assuming both no exercise and full exercise of the underwriters' option to purchase            additional shares.

Paid by State Street
   No Exercise
   Full Exercise
Per Share   $     $  
Total   $     $  

          Shares sold by the underwriters to the public will initially be offered at the public offering price set forth on the cover of this prospectus supplement. Any shares sold by the underwriters to securities dealers may be sold at a discount of up to $            per share from the public offering price. If all the shares are not sold at the public offering price, the representative may change the offering price and the other selling terms. The offering of the shares by the underwriters is subject to receipt and acceptance and subject to the underwriters' right to reject any order in whole or in part.

          State Street has agreed with the underwriters, subject to certain exceptions, not to dispose of or hedge any of their common stock or securities convertible into or exchangeable for shares of common stock during the period from the date of this prospectus supplement continuing through the date 60 days after the date of this prospectus supplement, except with the prior written consent of the representative. This agreement does not apply to any existing employee benefit plans.

          In connection with the offering, the underwriters may purchase and sell shares of common stock in the open market. These transactions may include short sales, stabilizing transactions and purchases to cover positions created by short sales. Short sales involve the sale by the underwriters of a greater number of shares than they are required to purchase in the offering. "Covered" short sales are sales made in an amount not greater than the underwriters' option to purchase additional shares from State Street in the offering. The underwriters may close out any covered short position by either exercising their option to purchase additional shares or purchasing shares in the open market. In determining the source of shares to close out the covered short position, the underwriters will consider, among other

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things, the price of shares available for purchase in the open market as compared to the price at which they may purchase additional shares pursuant to the option granted to them. "Naked" short sales are any sales in excess of such option. The underwriters must close out any naked short position by purchasing shares in the open market. A naked short position is more likely to be created if the underwriters are concerned that the price of the common stock in the open market may experience downward pressure after pricing that could adversely affect investors who purchase in the offering. Stabilizing transactions consist of various bids for or purchases of common stock made by the underwriters in the open market prior to the completion of the offering.

          The underwriters may also impose a penalty bid. This imposition occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representative has repurchased shares sold by or for the account of such underwriter in stabilizing or short covering transactions.

          Purchases to cover a short position and stabilizing transactions, as well as other purchases by the underwriters for their own accounts, may have the effect of preventing or retarding a decline in the market price of State Street's common stock, and together with the imposition of the penalty bid, may stabilize, maintain or otherwise affect the market price of the common stock. As a result, the price of the common stock may be higher than the price that otherwise might exist in the open market. If these activities are commenced, they may be discontinued at any time. These transactions may be effected on the New York Stock Exchange, in the over-the-counter market or otherwise.

European Economic Area

          In relation to each Member State of the European Economic Area which has implemented the Prospectus Directive (each, a Relevant Member State), each underwriter has represented and agreed that with effect from and including the date on which the Prospectus Directive is implemented in that Relevant Member State (the Relevant Implementation Date) it has not made and will not make an offer of shares to the public in that Relevant Member State prior to the publication of a prospectus in relation to the shares which has been approved by the competent authority in that Relevant Member State or, where appropriate, approved in another Relevant Member State and notified to the competent authority in that Relevant Member State, all in accordance with the Prospectus Directive, except that it may, with effect from and including the Relevant Implementation Date, make an offer of shares to the public in that Relevant Member State at any time:

          For the purposes of this provision, the expression an "offer of shares to the public" in relation to any shares in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and the shares to be offered so as to enable an investor to decide to purchase or subscribe the shares, as the same may be varied in that Relevant Member

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State by any measure implementing the Prospectus Directive in that Relevant Member State and the expression Prospectus Directive means Directive 2003/71/EC and includes any relevant implementing measure in each Relevant Member State.

          Each underwriter has represented and agreed that:

          The shares may not be offered or sold by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap.32, Laws of Hong Kong), or (ii) to "professional investors" within the meaning of the Securities and Futures Ordinance (Cap.571, Laws of Hong Kong) and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a "prospectus" within the meaning of the Companies Ordinance (Cap.32, Laws of Hong Kong), and no advertisement, invitation or document relating to the shares may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the laws of Hong Kong) other than with respect to shares which are or are intended to be disposed of only to persons outside Hong Kong or only to "professional investors" within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder.

          Neither this prospectus supplement nor the accompanying prospectus has been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus supplement, the accompanying prospectus, any free writing prospectus we authorize to be delivered to you and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the shares may not be circulated or distributed, nor may the shares be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore, or the SFA, (ii) to a relevant person, or any person pursuant to Section 275(1A), and in accordance with the conditions, specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

          Where the shares are subscribed or purchased under Section 275 by a relevant person which is: (a) a corporation (which is not an accredited investor) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or (b) a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary is an accredited investor, shares, debentures and units of shares and debentures of that corporation or the beneficiaries' rights and interest in that trust shall not be transferable for 6 months after that corporation or that trust has acquired the shares under Section 275 except: (1) to an institutional investor under Section 274 of the SFA or to a relevant person, or any person pursuant to Section 275(1A), and in accordance with the conditions, specified in Section 275 of the SFA; (2) where no consideration is given for the transfer; or (3) by operation of law.

          The securities have not been and will not be registered under the Securities and Exchange Law of Japan (the Securities and Exchange Law) and each underwriter has agreed that it will not offer or sell

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any securities, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others for re-offering or resale, directly or indirectly, in Japan or to a resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the Securities and Exchange Law and any other applicable laws, regulations and ministerial guidelines of Japan.

          State Street estimates that its share of the total expenses of the offering, excluding underwriting discounts and commissions, will be approximately $600,000.

          State Street has agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act of 1933.

          Certain of the underwriters and their respective affiliates have, from time to time, performed, and may in the future perform, various financial advisory and investment banking services for State Street, for which they received or will receive customary fees and expenses.

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VALIDITY OF SECURITIES

          Certain legal matters in connection with the offering of our common stock will be passed upon for us by Wilmer Cutler Pickering Hale and Dorr LLP, Boston, Massachusetts, and for the underwriters by Cravath, Swaine & Moore LLP, New York, New York.


EXPERTS

          The consolidated financial statements of State Street Corporation appearing in State Street Corporation's Annual Report on Form 10-K for the year ended December 31, 2007, and the effectiveness of State Street Corporation's internal control over financial reporting as of December 31, 2007 have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

          With respect to the unaudited condensed consolidated interim financial information of State Street Corporation for the three-month periods ended March 31, 2008 and March 31, 2007, incorporated by reference herein, Ernst & Young LLP reported that they have applied limited procedures in accordance with professional standards for a review of such information. However, their separate report dated May 8, 2008, included in State Street Corporation's Quarterly Report on Form 10-Q for the quarter ended March 31, 2008 and incorporated by reference herein, states that they did not audit and they do not express an opinion on that interim financial information. Accordingly, the degree of reliance on their report of such information should be restricted in light of the limited nature of the review procedures applied. Ernst & Young LLP is not subject to the liability provisions of Section 11 of the Securities Act of 1933 (the "Act") for their report on the unaudited interim financial information because that report is not a "report" or a "part" of the Registration Statement prepared or certified by Ernst & Young LLP within the meaning of Sections 7 and 11 of the Act.

S-36


WHERE YOU CAN FIND MORE INFORMATION

          We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC's website at http://www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at http://www.statestreet.com. Our website is not a part of this prospectus supplement. You may also read and copy any document we file at the SEC's public reference room, 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the operation of the public reference room.

          Because our common stock is listed on the New York Stock Exchange, you may also inspect reports, proxy statements and other information about us at the offices of the New York Stock Exchange, 20 Broad Street, New York, New York 10005.

          The SEC allows us to "incorporate by reference" information we file with it, which means that we can disclose important information to you by referring you to other documents. The information incorporated by reference is considered to be a part of this prospectus supplement and information that we file later with the SEC will automatically update and supersede this information. In all cases, you should rely on the later information over different information included in this prospectus supplement.

          We incorporate by reference the documents listed below and all future filings we make with the SEC under Section 13 (a), 13(c), 14 or 15(d) of the Exchange Act, prior to the termination of the offering, except to the extent that any information contained in such filings is deemed "furnished" in accordance with SEC rules:

          You may request a copy of these filings, at no cost, by writing or telephoning us at the following address:

State Street Corporation
One Lincoln Street
Boston, Massachusetts 02111
Telephone: (617) 786-3000
Attn: Corporate Secretary

S-37

State Street Corporation

Debt Securities
Preferred Stock
Depositary Shares
Common Stock
Stock Purchase Contracts
Stock Purchase Units
Warrants

State Street Capital Trust III
State Street Capital Trust IV

Capital Securities Fully and Unconditionally
Guaranteed by State Street Corporation

        State Street Corporation may offer and sell Debt Securities, Preferred Stock, Depositary Shares, Common Stock, Stock Purchase Contracts, Stock Purchase Units and Warrants. The Debt Securities and shares of our Preferred Stock may be convertible into or exchangeable for shares of our Common Stock or other securities.

        The trusts are Delaware statutory trusts. Each trust may from time to time:

        State Street Corporation will fully and unconditionally guarantee the payment by the trusts of the capital securities based on obligations discussed in this prospectus. This is called the capital securities guarantee.

        The common stock of State Street Corporation is listed on the New York Stock Exchange, the Boston Stock Exchange and the Archipelago Stock Exchange under the symbol "STT."

        We will provide specific terms of these securities in supplements to this prospectus. You should read this prospectus and any supplements carefully before you invest.

        You should fully consider the risk factors beginning on page 3 in this prospectus and in the accompanying prospectus supplement, if any, prior to investing in the offered securities.

        A security is not a deposit and the securities are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.

        This prospectus may be used to offer and sell securities only if accompanied by the prospectus supplement for those securities.

        Our principal executive offices are located at One Lincoln Street, Boston, Massachusetts 02111 and our telephone number is (617) 786-3000.

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is March 21, 2006

IMPORTANT NOTICE ABOUT INFORMATION PRESENTED IN THIS PROSPECTUS AND
THE ACCOMPANYING PROSPECTUS SUPPLEMENT

        We provide information to you about the securities in two separate documents that progressively provide more detail:

        If the terms of your securities vary between the prospectus supplement and this prospectus, you should rely on the information in the following order of priority:

        We include cross-references in this prospectus and the accompanying prospectus supplement to captions in these materials where you can find further related discussions. The Table of Contents included in this prospectus and the Table of Contents included in the accompanying prospectus supplement provide the pages on which these captions are located.

        Neither we nor the underwriters have taken any action that would permit us to publicly sell these securities in any jurisdiction outside the United States. If you are an investor outside the United States, you should inform yourself about and comply with any restrictions as to the offering of the securities and the distribution of this prospectus.

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TABLE OF CONTENTS

ABOUT THIS PROSPECTUS   1
WHERE YOU CAN FIND MORE INFORMATION   1
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE   1
FORWARD-LOOKING STATEMENTS   2
STATE STREET CORPORATION   7
CONSOLIDATED RATIOS OF EARNINGS TO FIXED CHARGES   8
USE OF PROCEEDS   8
DESCRIPTION OF DEBT SECURITIES   8
DESCRIPTION OF THE TRUSTS   17
DESCRIPTION OF THE JUNIOR SUBORDINATED DEBENTURES   18
DESCRIPTION OF THE CAPITAL SECURITIES   30
COMMON SECURITIES   41
DESCRIPTION OF THE CAPITAL SECURITIES GUARANTEES   41
RELATIONSHIP AMONG THE CAPITAL SECURITIES, THE CORRESPONDING JUNIOR SUBORDINATED DEBENTURES AND THE CAPITAL SECURITIES GUARANTEES   44
DESCRIPTION OF PREFERRED STOCK   46
DESCRIPTION OF DEPOSITARY SHARES   49
DESCRIPTION OF COMMON STOCK   51
DESCRIPTION OF STOCK PURCHASE CONTRACTS AND STOCK PURCHASE UNITS   53
DESCRIPTION OF WARRANTS   53
GLOBAL SECURITIES   54
PLAN OF DISTRIBUTION   61
VALIDITY OF SECURITIES   62
EXPERTS   62

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ABOUT THIS PROSPECTUS

        This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, which we refer to as the SEC, utilizing a "shelf" registration process. Under this shelf registration process, we may from time to time sell any combination of the securities described in this prospectus in one or more offerings. We may offer any of the following securities: debt securities, preferred stock, depositary shares, common stock, stock purchase contracts, stock purchase units, capital securities and related guarantees. We may also offer warrants to purchase debt securities, preferred stock, depositary shares or common stock. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any prospectus supplement together with the additional information described under the heading "Where You Can Find More Information." The prospectus supplement may also contain information about certain United States federal income tax considerations relating to the securities covered by the prospectus supplement.

        Unless otherwise indicated or unless the context requires otherwise, all references in this prospectus to "State Street," "we," "us," "our" or similar references mean State Street Corporation and its subsidiaries on a consolidated basis.


WHERE YOU CAN FIND MORE INFORMATION

        We have filed with the SEC a registration statement under the Securities Act of 1933 that registers, among other securities, the offer and sale of the securities offered by this prospectus. The registration statement, including the attached exhibits and schedules, contains additional relevant information about us. The rules and regulations of the SEC allow us to omit certain information included in the registration statement from this prospectus.

        In addition, we file reports, proxy statements and other information with the SEC under the Exchange Act. You may read and copy this information at the SEC's Public Reference Room, located at 100 F Street, N.E., Washington, D.C. 20549. You may obtain information on the operation of the Public Reference Room by calling the SEC at 1-800-SEC-0330.

        You may also obtain copies of this information by mail from the Public Reference Section of the SEC, 100 F Street, N.E., Washington, D.C. 20549, at prescribed rates.

        The SEC also maintains an Internet worldwide web site that contains reports, proxy statements and other information about issuers, like us, who file electronically with the SEC. The address of that site is http://www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at http://www.statestreet.com. Our website is not a part of this prospectus.

        You can also inspect reports, proxy statements and other information about us at the offices of the New York Stock Exchange, 20 Broad Street, New York, New York 10005.


INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

        The SEC allows us to "incorporate by reference" information into this prospectus. This means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is considered to be a part of this prospectus, except for any information that is superseded by information that is included directly in this document or in a more recent incorporated document.

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        This prospectus incorporates by reference the documents listed below that we have previously filed with the SEC. They contain important information about us and our financial condition.

SEC Filings
   Period
Annual Report on Form 10-K   Year Ended December 31, 2005
Current Reports on Form 8-K   Filed January 18, 2006
Filed February 7, 2006
Filed March 7, 2006

Registration Statement on Form 8-A
(relating to Common Stock)
 
Filed on January 18, 1995 and March 7, 1995
Registration Statement on Form 8-A
(relating to preferred stock purchase rights)		   Filed on January 18, 1995 and March 7, 1995, and as amended on July 7, 1998

        We incorporate by reference additional documents that we may file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act between the date of this prospectus and the date we sell all of the securities. These documents include periodic reports, such as Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as proxy statements.

        You can obtain any of the documents incorporated by reference in this document through us, or from the SEC through the SEC's Internet web site at the address described previously. Documents incorporated by reference are available from us without charge, excluding any exhibits to those documents, unless the exhibit is specifically incorporated by reference as an exhibit to the registration statement. You may obtain documents incorporated by reference in this prospectus by requesting them in writing or by telephone from us at the following address:

State Street Corporation
Investor Relations
One Lincoln Street
Boston, Massachusetts 02111
(617) 664-3477

        We have not authorized anyone to give any information or make any representation about us that is different from, or in addition to, the information and representations contained in this prospectus or in any of the materials that we have incorporated into this prospectus. If anyone does give you information of this sort, you should not rely on it. If you are in a jurisdiction where offers to sell, or solicitations of offers to purchase, the securities offered by this document are unlawful, or if you are a person to whom it is unlawful to direct these types of activities, then the offer presented in this document does not extend to you. The information contained in this document speaks only as of the date of this document unless the information specifically indicates that another date applies.


FORWARD-LOOKING STATEMENTS

        This prospectus, including information incorporated by reference, contains statements that are considered "forward-looking statements" within the meaning of U.S. federal securities laws. In addition, we may make other written or oral communications from time to time that contain forward-looking statements. Forward-looking statements, including statements as to industry trends, future expectations of State Street and other matters that do not relate strictly to historical facts, are based on certain assumptions by management, and are often identified by such forward-looking terminology as "expect," "look," "believe," "anticipate," "may," "will," "trend" and "goal," or similar statements or variations of such terms. Forward-looking statements may include statements about our confidence and strategies and our expectations about revenue and market growth, acquisitions and divestitures, new technologies, services and opportunities, and earnings. Forward-looking statements are based on information we have

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when those statements are made or on management's belief as of that time with respect to future events, and are subject to various risks and uncertainties, which change over time, and could cause actual results to differ materially from those contemplated by the forward-looking statements. Such forward-looking statements speak only as of the date they are made.


RISK FACTORS

        Before you invest in our securities, you should understand and carefully consider the risks below, as well as all other information contained in this prospectus and in our consolidated financial statements and related notes thereto. You also should consider the risks set forth in Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2005, which is incorporated by reference in this prospectus, as the same may be amended, supplemented or superseded from time to time by our future filings with the SEC under the Exchange Act. Any of these risks could materially adversely affect our business, our consolidated financial condition and our consolidated results of operations and cause our future results to differ materially from our historical performance.

If market interest rates rise, our securities finance and net interest revenues can be negatively affected in the short term.

        The levels of global market interest rates, the shape of the yield curve, the direction and speed of interest rate changes, and the asset and liability spreads relative to the currency and geographic mix of our interest-bearing assets and interest-bearing liabilities affect our securities finance and net interest revenue. In the short term, our net interest revenue and securities finance revenue benefit from falling interest rates and are negatively affected by rising interest rates because our interest-bearing liabilities generally reprice sooner than our interest-earning assets. The rate of adjustment to higher or lower rates will depend on the relative duration of assets and liabilities. In general, sustained lower interest rates, a flat yield curve and narrow interest-rate spreads have a constraining effect on net interest revenue and securities finance revenue growth. Market interest rates, which affect the economic value of our demand deposits, also impact the value of certain derivative financial instruments whose changes in value are reflected in trading services and processing fees and other revenue in our consolidated statement of income.

If values in worldwide securities markets decline, our revenue and earnings can be adversely affected.

        As asset values in worldwide financial markets increase or decrease, our opportunities to invest and service financial assets change. Because a portion of our fees is based on the value of assets under custody and management, fluctuations in the valuation of worldwide securities markets will affect revenue. We estimate that a 10% increase or decrease in worldwide equity values would result in a corresponding change in our total revenue of approximately 2%. If fixed income security values worldwide were to increase or decrease by 10%, we would anticipate a corresponding change of approximately 1% in our total revenue. Because many of the costs of providing our services are relatively fixed, a decline in revenue could have a disproportionate effect on our earnings.

If foreign exchange rate volatility decreases, our revenue can be adversely affected.

        The degree of volatility in foreign exchange rates can affect our foreign exchange trading revenue. In general, we benefit from currency volatility, and foreign exchange revenue is likely to decrease during times of decreased currency volatility. In addition, as our business grows globally, our exposure to changes in foreign currency exchange rates could impact our level of revenue, expense and net income and the value of our investments in our non-U.S. operations.

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If we do not maintain our capital requirements and our status as a "well-capitalized" financial holding company, there could be an adverse effect on the manner in which we do business and on the confidence of our customers in us.

        Under regulatory capital adequacy guidelines, we and our principal banking subsidiary, State Street Bank and Trust Company, or "State Street Bank," must meet guidelines that involve quantitative measures of assets, liabilities and certain off-balance sheet items. Failure to meet minimum capital requirements could have a material effect on our financial condition and could subject us to a variety of enforcement actions, as well as certain restrictions on our business. Failure to maintain the status of "well capitalized" under the regulatory framework could affect our status as a financial holding company and eligibility for a streamlined review process for acquisition proposals, and deterioration in the confidence that our customers have in us, which can lead to a decline in the demand for our products and affect the prices that we are able to charge for our services. In addition to being well-capitalized, State Street and State Street Bank are subject to guidelines that involve qualitative judgments by regulators about the entities' status as well-managed and the entities' compliance with Community Reinvestment Act obligations.

If there is a decline in individual savings rates, our business can be adversely affected.

        We generally benefit when individuals invest their savings in mutual funds, other collective funds and defined contribution plans. Changes in savings rates or investment styles may affect revenue. If there is a decline in the savings rates of individuals, or if there is a change in investment preferences that leads to fewer investments in mutual funds, other collective investment funds, and defined contribution plans, our revenue may be adversely affected.

While increased cross-border investing by our customers worldwide benefits our revenue, increased worldwide economic and political instability can adversely affect our business.

        Our revenue may increase or decrease depending upon the extent of increases or decreases in cross-border investments made by our customers. The terrorist attacks that took place in the United States on September 11, 2001, and subsequent military action and terrorist activities, have caused economic and political uncertainties. These activities and the national and global efforts to combat terrorism, and other military activities and outbreaks of hostilities have affected and may further adversely affect economic growth. Such events could result in decreased cross-border investment activities and may have other adverse effects on many companies, including ours, in ways that are not predictable.

If there is a decline in the pace at which customers outsource their middle office or investment management operations, our business can be adversely affected.

        In recent years, investment manager and hedge fund manager operations outsourcing have been areas of rapid growth in our business. If the demand for these types of services declines, we could see a slowing in the growth rate of our revenue.

If we do not perform effectively under our outsourcing contracts, we may not generate the operating margins that we expect, or we may lose customers before we earn back our investment in the contracts.

        We enter into long-term contracts to provide middle office or investment manager and hedge fund manager operations outsourcing services to customers. Services that we provide include trade order management, trade support and fail management, reconciliations, cash reporting and management, custodian communications for settlements, accounting systems, collateral management and information technology development. These contracts often extend eight to ten years and require considerable up-front investments by us, including technology and conversion costs. Performance risk exists in each

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contract, since these contracts are dependent upon the successful conversion and implementation of the activities onto our own operating platforms. Our operating margins, and as a result our profitability, are largely a function of our ability to accurately calculate pricing for our services, our ability to control our costs and our ability to maintain the relationship with the customer for an adequate period of time to recover the up-front investment. The long-term nature of these contracts creates a risk that our pricing for the products and services we provide might not be adequate to generate expected operating margins.

If we do not successfully integrate businesses that we acquire, or successfully complete divestitures, we may not realize the expected benefits of the transaction.

        Acquisitions of complementary businesses and technologies, development of strategic alliances and divestitures of portions of our business are an active part of our overall business strategy. We have completed several acquisitions, alliances and divestitures in recent years. However, there can be no assurance that services, technologies, key personnel or businesses of acquired companies will be effectively assimilated into our business or service offerings, that alliances will be successful, or that related expectations concerning future revenue growth or cost savings will be achieved. In addition, we may not be able to successfully manage the conversion of divested businesses to the buyer on satisfactory terms, if at all, and divestitures may result in a reduction of total revenue and net income.

If we are subject to changes in tax legislation, the interpretation of existing tax laws worldwide or changes in accounting principles, we may be required to report a material charge to our results of operations.

        In the normal course of business, we are subject to challenges from U.S. and non-U.S. tax authorities regarding the amount of taxes due. These challenges may result in adjustments to the timing or amount of taxable income or deductions or the allocation of income among tax jurisdictions. In recent years, the U.S. Internal Revenue Service, or "IRS," has proposed to disallow tax deductions related to cross-border leasing transactions, which could have an adverse impact on our results of operations. Additionally, the Financial Accounting Standards Board has been considering making changes to the accounting guidance related to uncertain tax positions and leveraged leases. While such changes may not have an economic impact on our business, these changes could affect the attainment of our current financial goals.

If the pace of pension reform slows, or if pension reform does not occur, our revenue and earnings can be adversely affected.

        We expect our business to benefit from worldwide pension reform that creates additional pools of assets that use custody and related services, and investment management services. The pace of pension reform and resulting programs, including public and private pension schemes, may affect the pace of our revenue growth.

If we do not maintain compliance with governmental regulation, we can be subject to fines, penalties or restrictions of business in the jurisdiction where the violation occurred, which can adversely impact our business.

        Our businesses are subject to stringent regulation and examination by U.S. federal and state governmental and regulatory agencies and self-regulatory organizations (including securities exchanges), and by non-U.S. governmental and regulatory agencies and self-regulatory organizations. In addition, our customers have a broad array of complex and specialized servicing, confidentiality and fiduciary requirements. We have established policies, procedures and systems designed to comply with these regulatory and operational risk requirements. However, as a global financial services institution, we face complexity and costs in our worldwide compliance efforts. We also face the potential for loss resulting

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from inadequate or failed internal processes, employee supervisory or monitoring mechanisms, or other systems or controls, and from external events, which could have a material impact on our future results of operations. Also, adverse publicity and damage to our reputation arising from the failure or perceived failure to comply with legal, regulatory or contractual requirements could affect our ability to attract and retain customers or maintain access to capital markets, or could result in enforcement actions, fines, penalties and lawsuits.

If, for regulatory reasons, we are limited in our ability to invest additional capital in subsidiaries outside the United States, we may not be able to stay competitive in those markets, and our business could suffer.

        Federal laws and related regulations limit the amount that banks, including State Street Bank, may invest in non-U.S. subsidiaries. This limitation could affect the pace of future international expansion by State Street Bank through this type of subsidiary.

Investigations into the financial services industry can adversely affect our business.

        We are broadly involved with the global securities industry including, in particular, the mutual fund industry. Financial reporting irregularities involving large and well-known companies, and governmental and regulatory investigations of securities and mutual fund industry practices and behavior, may have adverse effects on us in ways that are not predictable. Governmental and regulatory agencies have sought information from us in connection with investigations relating to that industry that has resulted in additional expenses and staffing resources in providing responses.

If the business continuity and disaster recovery plans that we have in place are not adequate to continue our operations in the event of a disaster, the business disruption can adversely impact our operations.

        External events, including terrorist or military actions, or an outbreak of disease, such as Asian Influenza, or "bird flu," and resulting political and social turmoil could cause unforeseen damage to our physical facilities, or could cause delays or disruptions to operational functions, including information processing and financial market settlement functions. Additionally, our customers, vendors and counterparties could suffer from such events. Should these events affect us, or the customers, vendors or counterparties with which we conduct business, our results of operations could be adversely affected.

If we are not able to anticipate and keep pace with rapid changes in technology, or do not respond to rapid technological changes in our industry, or if growth in the use of technology in business is not as rapid as in the past, our business can be adversely affected.

        Technological change often creates opportunities for product differentiation and reduced costs, as well as the possibility of increased expenses. Developments in the securities processing industry, including shortened settlement cycles and straight-through-processing, will result in changes to existing procedures. Alternative delivery systems have emerged, including the widespread use of the Internet. Our financial performance depends, in part, on our ability to develop and market new and innovative services, and to adopt or develop new technologies that differentiate our products or provide cost efficiencies. The risks inherent in this process include rapid technological change in the industry, our ability to access technical and other information from customers, and the significant and ongoing investments required to bring new services to market in a timely fashion at competitive prices. A further risk is the introduction by competitors of services that could replace or provide lower-cost alternatives to our services.

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If we are unsuccessful in protecting our proprietary rights, or if we are found to have violated the proprietary rights of others, we can experience a decline in revenue or an increase in expenses.

        We use trademark, trade secret, copyright, patent and other proprietary rights procedures to protect our technology. Despite these efforts, we cannot be certain that the steps taken by us to prevent unauthorized use of proprietary rights are sufficient to prevent misappropriation of technology, particularly outside the United States where laws or law enforcement practices may not protect proprietary rights as fully as in the U.S. In addition, no assurance can be given that the courts will adequately enforce contractual agreements that we have entered into to protect our proprietary technology. If any of our proprietary information were misappropriated by, or otherwise disclosed to, our competitors, our competitive position could be adversely affected. In the event a third party asserts a claim of infringement of its proprietary rights, obtained through patents or otherwise, against us, we may be required to spend significant resources to defend against such claims, develop a non-infringing program or process, or obtain a license to the infringed process.

If our access to the capital markets is limited, our capital resources and liquidity could be adversely affected.

        We depend on access to global capital markets to provide us with sufficient capital resources and liquidity to meet our commitments and business needs and accommodate the transaction and cash management needs of our customers. Any occurrence that may limit our access to the capital markets, such as a decline in the confidence of debt purchasers, depositors or counterparties participating in the capital markets in general or with us in particular, or a downgrade of our debt rating, may adversely affect our capital costs and our ability to raise capital and, in turn, our liquidity.

If there is a significant economic downturn in either a country or a region, or the failure of a significant individual counterparty, our credit and counterparty risk profile could be adversely affected and result in loss.

        Our focus on large institutional investors and their businesses requires that we assume credit and counterparty risk, both on-and off-balance sheet, in a variety of forms. We provide, on a limited basis, traditional loan products to customers, based upon credit quality and other factors. We also provide customers with off-balance sheet liquidity and credit enhancement facilities in the form of letters of credit, lines of credit and liquidity asset purchase agreements, subject to credit analysis and an approval and review process. We invest in financial instruments, including investment securities and derivative instruments, which are also subject to risk management processes.

        The credit quality of our on- and off-balance sheet exposures may be affected by many factors, such as economic and business conditions or deterioration in the financial condition of an individual counterparty or group of counterparties. In the event of poor economic conditions in a particular country or region, or the failure of a significant counterparty or group of counterparties, there is a greater likelihood that more of our customers or counterparties could become delinquent on their loans or other obligations to us, or that the special purpose entities we administer could experience deterioration in asset performance. This could result in higher levels of credit-related losses, which could adversely affect our earnings.


STATE STREET CORPORATION

        We are a bank holding company organized under the laws of the Commonwealth of Massachusetts and a leading provider of services to institutional investors and investment managers worldwide. We were organized in 1970 and conduct our business principally through our subsidiary, State Street Bank which traces its beginnings to the founding of Union Bank in 1792. The charter under which State Street Bank now operates was authorized by a special act of the Massachusetts Legislature in 1891, and

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its present name was adopted in 1960. We are also a financial holding company. Our executive offices are located at One Lincoln Street, Boston, Massachusetts 02111 and our telephone number is (617) 786-3000.


CONSOLIDATED RATIOS OF EARNINGS TO FIXED CHARGES

        Our consolidated ratios of earnings to fixed charges were as follows for the five most recent fiscal years:

 
   Year Ended December 31,
 
   2005
   2004
   2003
   2002
   2001
Ratio of earnings to fixed charges   1.70x   2.24x   2.41x   2.48x   1.50x

        Under SEC regulations and for the purposes of calculating these ratios, earnings consist primarily of income from continuing operations before income taxes and fixed charges. Fixed charges consist of interest on indebtedness, amortization of debt issuance costs and the interest component of rental expense.


USE OF PROCEEDS

        We intend to use the net proceeds from the sale of the securities for general corporate purposes unless otherwise indicated in the prospectus supplement or term sheet relating to a specific issue of securities. Our general corporate purposes may include extending credit to, or funding investments in, our subsidiaries. The precise amounts and the timing of our use of the net proceeds will depend upon our subsidiaries' funding requirements and the availability of other funds. Until we use the net proceeds from the sale of any of our securities for general corporate purposes, we will use the net proceeds to reduce our short-term indebtedness or for temporary investments. We expect that we will, on a recurrent basis, engage in additional financings as the need arises to finance our growth, through acquisitions or otherwise, or to fund our subsidiaries. We and State Street Bank regularly investigate possible acquisitions.


DESCRIPTION OF DEBT SECURITIES

        The senior debt securities will be issued under an indenture dated as of August 2, 1993 (the senior indenture) between us and U.S. Bank National Association, as successor senior trustee. The subordinated debt securities (other than the junior subordinated debentures) will be issued under an indenture dated as of June 15, 2000 (the subordinated indenture) between us and J.P. Morgan Chase & Co., as subordinated trustee and as successor in interest to Bank One Trust Company, N.A. A copy of each indenture is included as an exhibit to the registration statement that contains this prospectus.

        The following summaries of all material terms of the indentures are not complete and are subject to, and are qualified in their entirety by reference to, all the provisions of the respective indentures, including the definitions of terms. The following summaries describe the general terms and provisions of the debt securities to be offered by any prospectus supplement. The particular terms of the debt securities offered by any prospectus supplement and the extent, if any, to which these general provisions may apply to the debt securities so offered, will be described in the prospectus supplement relating to such offered securities.

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        The senior debt securities will be unsecured and will rank equally with all other unsecured and unsubordinated indebtedness of State Street. The subordinated debt securities will be unsecured and will be subordinated to all existing and future senior indebtedness and other financial obligations of State Street as described under "—Subordinated Debt Securities—Subordination" beginning on page 15. Because we are a holding company, our rights and the rights of our creditors, including the holders of the debt securities we are offering under this prospectus, to participate in the assets of any of our subsidiaries upon the subsidiary's liquidation or reorganization will be subject to the prior claims of the subsidiary's creditors except to the extent that we may ourselves be a creditor with recognized claims against the subsidiary. In addition, dividends, loans and advances from certain of our banking subsidiaries to us and our non-banking subsidiaries are restricted by federal and state statutes and regulations.

General

        We may issue the debt securities from time to time, without limitation as to aggregate principal amount and in one or more series. We expect from time to time to incur additional indebtedness that may be senior to the debt securities. Neither the indentures nor the debt securities will limit or otherwise restrict the amount of other indebtedness which may be incurred or other securities which may be issued by us or our subsidiaries, including indebtedness which may rank senior to the debt securities. The debt securities will not be secured.

        We may issue debt securities upon the satisfaction of conditions contained in the indentures. The applicable prospectus supplement will include the terms of that issue of debt securities, including:

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        Please see the accompanying prospectus supplement or the term sheet you have received or will receive for the terms of the specific debt securities we are offering. We may deliver this prospectus before or concurrently with the delivery of a term sheet. We may issue debt securities under the indentures upon the exercise of warrants to purchase debt securities. Please see "Description of Warrants." Nothing in the indentures or in the terms of the debt securities will prohibit the issuance of securities representing subordinated indebtedness that is senior or junior to the subordinated debt securities.

        Prospective purchasers of debt securities should be aware that special federal income tax, accounting and other considerations may be applicable to instruments such as the debt securities. The prospectus supplement relating to an issue of debt securities will describe these considerations, if they apply.

        Debt securities may be issued as original issue discount securities which bear no interest or interest at a rate which at the time of issuance is below market rates and which will be sold at a substantial discount below their principal amount. In the event that the maturity of any original issue discount security is accelerated, the amount payable to the holder of the original issue discount security upon acceleration will be determined in accordance with the applicable prospectus supplement, the terms of such security and the relevant indenture, but will be an amount less than the amount payable at the maturity of the principal of such original issue discount security. Special federal income tax and other considerations relating to original issue discount securities will be described in the applicable prospectus supplement.

        The indentures provide that without the consent of any holders, we and the trustee may enter into one or more supplemental indentures for certain purposes, including:


        In the event any sinking fund is established for the retirement of debt securities of any series, we may satisfy all or any part of the sinking fund payments with debt securities of such series under certain circumstances and to the extent provided for by the terms of such debt securities.

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        Unless otherwise indicated in the applicable prospectus supplement, the covenants contained in the indentures and the debt securities will not protect holders in the event of a sudden decline in our creditworthiness that might result from a recapitalization, restructuring or other highly leveraged transaction.

Registration and Transfer

        Unless otherwise indicated in the applicable prospectus supplement, we will issue each series of debt securities in registered form only, without coupons and in denominations of $1,000 or integral multiples thereof. Holders may present debt securities in registered form for transfer or exchange for other debt securities of the same series at the office or agency of State Street maintained for such purpose.

        No service charge will be made for any transfer or exchange of the debt securities but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with any transfer or exchange.

Payment and Place of Payment

        Unless otherwise indicated in the applicable prospectus supplement, we will pay principal of and any premium and interest on the debt securities at the office or agency of State Street maintained for such purpose. However, at our option, we may pay any interest by check mailed to the holders of registered debt securities at their registered addresses.

Events of Default

        The following are "events of default" under the senior indenture and "defaults" under the subordinated indenture with respect to any series of debt securities:

        If an event of default under the senior indenture occurs and is continuing for any series of debt securities, the senior trustee or the holders of at least 25% in aggregate principal amount or issue price of the outstanding securities of that series may declare the principal amount of all the securities of that series, or any lesser amount provided for in the debt securities of that series, to be due and payable or deliverable immediately. At any time after the senior trustee or the holders have accelerated any series of debt securities, but before the senior trustee has obtained a judgment or decree for payment of money due or delivery of the maturity consideration, the holders of a majority in aggregate principal amount or issue price of outstanding debt securities of that series may, under certain circumstances, rescind and annul such acceleration.

        Under the subordinated indenture, an "event of default" is limited to certain events involving the bankruptcy, insolvency or reorganization of State Street. The subordinated debt securities will

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automatically be accelerated upon the occurrence of an "event of default" resulting from bankruptcy, insolvency or reorganization. In the case of a default in the payment of interest or principal, or premium, if any, State Street will be required, upon the demand of the trustee, to pay to it, for the benefit of the holders of the subordinated debt securities, the whole amount then due and payable on such subordinated debt securities for principal, including any sinking fund payment or analogous obligations, and premium, if any, and interest and, to the extent that payment of such interest shall be legally enforceable, interest on any overdue principal, and premium, if any, and on any overdue interest, at the rate or rates prescribed in such subordinated debt securities. In the case of any default with respect to the subordinated debt securities, the trustee may in its discretion proceed to protect and enforce its rights and the rights of the holders of the subordinated debt securities by such appropriate judicial proceedings as the trustee shall deem most effectual to protect and enforce any such rights, whether for the specific enforcement of any such covenant or in aid of the exercise of any power granted in the subordinated indenture, or to enforce any other proper remedy.

        The holders of a majority in principal amount or aggregate issue price of the outstanding debt securities of any series may waive an event of default with respect to that series, except a default:

        The holders of a majority in principal amount or issue price of the outstanding debt securities of a series may direct the time, method and place of conducting any proceeding for any remedy available to the applicable trustee or exercising any trust or power conferred on the trustee with respect to debt securities of that series, provided that any such direction is not in conflict with any rule of law or the indenture. Subject to the provisions of the indenture relating to the duties of the trustee, before proceeding to exercise any right or power under the indenture at the direction of the holders, the trustee is entitled to receive from those holders reasonable security or indemnity against the costs, expenses and liabilities which might be incurred by it in complying with any direction.

        A holder of any debt security of any series will have the right to institute a proceeding with respect to the indenture or for any remedy thereunder, if:

        However, any holder of a debt security has the absolute right to institute suit for any defaulted payment after the due dates for payment under that debt security.

        We are required to furnish to the trustees annually a statement as to the performance of our obligations under the indentures and as to any default in such performance.

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Modification and Waiver

        Each indenture may be modified and amended by us and the applicable trustee with the consent of holders of at least 662/3% in principal amount or issue price of each series of debt securities affected. However, without the consent of each holder of any debt security affected, we may not amend or modify any indenture to:

        From time to time we and the applicable trustee may, without the consent of the holders of the debt securities, waive or supplement each indenture for specified purposes, including, among other things:

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        The holders of at least a majority in principal amount of the outstanding debt securities of any series may, with respect to that series, waive past defaults under the applicable indenture, except as described under "Events of Default, Waiver and Notice" beginning on page 24.

Consolidation, Merger and Sale of Assets

        Unless otherwise indicated in the applicable prospectus supplement, we may consolidate or merge with or into any other corporation, and we may sell, lease or convey all or substantially all of our assets to any corporation, provided that:

Regarding the Trustees

        U.S. Bank National Association is the trustee under the senior indenture. J.P. Morgan Chase & Co., as successor in interest to Bank One Trust Company, N.A., is the trustee under the subordinated indenture. We and certain of our subsidiaries, including State Street Bank, maintain banking relations with the trustees in the ordinary course of business.

International Offering

        If specified in the applicable prospectus supplement, we may issue debt securities outside the United States. Such debt securities may be issued in bearer form and will be described in the applicable prospectus supplement. In connection with any offering outside the United States, we will designate paying agents, registrars or other agents with respect to the debt securities, as specified in the applicable prospectus supplement.

        Debt securities issued outside the United States may be subject to certain selling restrictions which will be described in the applicable prospectus supplement. These debt securities may be listed on one or more foreign stock exchanges as described in the applicable prospectus supplement. Special United States tax and other considerations, if any, applicable to an offering outside the United States will be described in the applicable prospectus supplement.

Limitation Upon Disposition of Voting Stock or Assets of State Street Bank

        The senior indenture prohibits us and State Street Bank, so long as any of the senior debt securities are outstanding, from selling or otherwise disposing of, or granting a security interest in or permitting the issuance of, any voting stock or any security convertible or exercisable into voting stock of State Street Bank or any of our subsidiaries that owns voting stock or any security convertible or exercisable into voting stock of State Street Bank.

        This restriction does not apply to dispositions made by us or any subsidiary:

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        The subordinated indenture does not contain a similar restriction on our ability to engage in or permit such transactions to occur.

Defeasance

        We may terminate or "defease" our obligations under the indentures of any series of debt securities, provided that certain conditions are met, including:


Subordinated Debt Securities

        The subordinated debt securities will be our direct, unsecured obligations. Unless otherwise specified in the applicable prospectus supplement, the subordinated debt securities will rank equally with all of our outstanding subordinated indebtedness that is not specifically stated to be junior to the subordinated debt securities.

Subordination

        The subordinated debt securities will be subordinated in right of payment to all senior indebtedness (as defined below). In certain events of insolvency, payments on the subordinated debt securities will also be effectively subordinated in right of payment to all "other financial obligations," (as defined below). In certain circumstances relating to our liquidation, dissolution, winding up, reorganization, insolvency or similar proceedings, the holders of all senior indebtedness will first be entitled to receive payment in full before the holders of the subordinated debt securities will be entitled to receive any payment on the subordinated debt securities. If, after all payments have been made to the holders of senior indebtedness, (A) there are amounts available for payment on the subordinated debt securities and (B) any person entitled to payment according to the terms of our other financial obligations has not received full payment, then amounts available for payments on the subordinated debt securities will first be used to pay in full such other financial obligations before any payment may be made on the subordinated debt securities.

        In the event of the acceleration of the maturity of any debt securities, all senior indebtedness and other financial obligations will have to be repaid before any payment can be made on the subordinated debt securities.

        In addition, no payment may be made on the subordinated debt securities in the event:

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        By reason of this subordination in favor of the holders of senior indebtedness, in the event of an insolvency, our creditors who are not holders of senior indebtedness or the subordinated debt securities may recover proportionately less than holders of senior indebtedness and may recover proportionately more than holders of the subordinated debt securities. By reason of the obligation of the holders of subordinated debt securities to pay over any amount remaining after payment of senior indebtedness to persons in respect of our other financial obligations, in the event of insolvency, holders of our existing subordinated indebtedness may recover more, ratably, than the holders of subordinated debt securities.

        Unless otherwise specified in the prospectus supplement relating to the particular series of subordinated debt securities, senior indebtedness is defined in the subordinated indenture as the principal of, premium, if any, and interest on:

        The term indebtedness means indebtedness, whether secured or unsecured, for which we or any corporation that succeeds to our business as permitted under the subordinated indenture, is liable directly or indirectly by guarantee, letter of credit, obligation to purchase or otherwise:


        Unless otherwise specified in the prospectus supplement relating to the particular series of subordinated debt securities offered thereby, other financial obligations means:

        As of December 31, 2005, we had approximately $1,985,000,000 in subordinated debt outstanding and approximately $674,000,000 of senior indebtedness and other financial obligations outstanding.

        The subordinated indenture does not limit or prohibit the incurrence by us or any of our subsidiaries, including State Street Bank, of additional senior indebtedness or other financial obligations, which may include indebtedness that is senior to the subordinated debt securities, but subordinate to our other obligations. Any prospectus supplement relating to a particular series of subordinated debt securities will set forth the aggregate amount of our indebtedness senior to the subordinated debt securities as of a recent date.

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        The subordinated debt securities shall rank equal in right of payment with each other and with our existing subordinated indebtedness, subject to the obligations of the holders of subordinated debt securities to pay over amounts remaining after payment of senior indebtedness to persons in respect of other financial obligations.

        The prospectus supplement may further describe the provisions, if any, which may apply to the subordination of the subordinated debt securities of a particular series.

Restrictive Covenants

        The subordinated indenture does not contain any significant restrictive covenants. The prospectus supplement relating to a series of subordinated debt securities may describe certain restrictive covenants, if any, to which we may be bound under the subordinated indenture.

Governing Law

        Both indentures are, and the senior debt securities and subordinated debt securities will be, governed by and construed in accordance with the laws of the State of New York.


DESCRIPTION OF THE TRUSTS

        Each of the trusts is a statutory trust formed under Delaware law pursuant to a trust agreement, signed by State Street, as depositor of each trust, and the property trustee, the Delaware trustee and the administrative trustees (each as defined below), and the filing of a certificate of trust with the Delaware Secretary of State. The trust agreement of each trust will be amended and restated in its entirety (each as so amended and restated, a trust agreement) prior to the issuance of capital securities by the trust, substantially in the form filed as an exhibit to the registration statement of which this prospectus forms a part. Each trust agreement will be qualified as an indenture under the Trust Indenture Act of 1939, as amended.

        Each trust exists for the exclusive purposes of:

        All of the common securities will be directly or indirectly owned by us. The common securities of each trust will rank equally, and payments will be made pro rata with the capital securities of that trust, except that upon an event of default under the trust agreement, the rights of the holders of the common securities to payment in respect of distributions and payments upon liquidation, redemption and otherwise will be subordinated to the rights of the holders of the capital securities. We will acquire common securities of each trust in an aggregate liquidation amount equal to at least three percent of the total capital of each trust.

        Each trust's business and affairs will be conducted by its trustees, each appointed by State Street as holder of the common securities. The trustees of each trust will be J.P Morgan Chase and Co. (as successor in interest to Bank One Trust Company, N.A.), as the property trustee, Chase Bank USA, National Association, as the Delaware trustee and two individual trustees, the administrative trustees, who are employees or officers of or affiliated with State Street. J.P. Morgan Chase & Co., as property trustee, will act as sole trustee under each trust agreement for purposes of compliance with the Trust Indenture Act. J.P. Morgan Chase & Co. will also act as trustee under the guarantees and the junior

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subordinated indenture. See "Description of the Capital Securities Guarantees" and "Description of the Junior Subordinated Debentures."

        The holder of the common securities of each trust, or the holders of a majority in liquidation amount of the trust's capital securities if an event of default under the trust agreement has occurred and is continuing, will be entitled to appoint, remove or replace the property trustee and/or the Delaware trustee for such trust. The right to vote to appoint, remove or replace the administrative trustees is vested exclusively in the holders of the common securities, and in no event will the holders of capital securities have such right.

        Unless otherwise specified in the applicable prospectus supplement, each trust has a term of approximately 55 years, but may be terminated earlier as provided in the applicable trust agreement.

        State Street will pay all fees and expenses related to the trusts and the offering of trust securities.

        The principal executive office of each trust is c/o State Street Bank and Trust Company, N.A., Two World Financial Center, 225 Liberty Street, New York, New York 10281, telephone number (917) 790-4000.


DESCRIPTION OF THE JUNIOR SUBORDINATED DEBENTURES

        We may issue junior subordinated debentures from time to time in one or more series under a junior subordinated indenture, dated as of December 15, 1996, as supplemented from time to time between us and J.P. Morgan Chase & Co. (as successor in interest to Bank One Trust Company, N.A.), as trustee, who we refer to as the debenture trustee. The junior subordinated indenture is qualified under the Trust Indenture Act, and terms of the junior subordinated debentures will include those stated in the junior subordinated indenture and those made part of the junior subordinated indenture by reference to the Trust Indenture Act.

        Set forth below is a description of the general terms of the junior subordinated debentures in which the trusts will invest the proceeds from the issuance and sale of the trust securities. The particular terms of the junior subordinated debentures will be described in the prospectus supplement relating to the particular capital securities being offered. The following description is not intended to be complete and is qualified by the junior subordinated indenture, which is filed as an exhibit to the registration statement which contains this prospectus, and the Trust Indenture Act.

General

        We will issue the junior subordinated debentures as unsecured debt. The junior subordinated debentures will be fully subordinated as set forth in the junior subordinated indenture. See "Subordination" below. Each series of junior subordinated debentures will rank equally with all other series of junior subordinated indentures. The junior subordinated indenture does not limit the aggregate principal amount of junior subordinated debentures which may be issued and provides that the junior subordinated debentures may be issued from time to time in one or more series. Because we are a holding company, our rights and the rights of our creditors, including the holders of the junior subordinated debentures, to participate in the assets of any of our subsidiaries upon the subsidiary's liquidation or reorganization will be subject to the prior claims of the subsidiary's creditors except to the extent that we may ourselves be a creditor with recognized claims against the subsidiary. Except as otherwise provided in the applicable prospectus supplement, the junior subordinated indenture does not limit the incurrence or issuance by us of other secured or unsecured debt.

        The prospectus supplement relating to the particular junior subordinated debentures being offered will describe the terms of those securities, which may include:

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        Junior subordinated debentures may be sold at a substantial discount below their stated principal amount, bearing no interest or interest at a rate which at the time of issuance is below market rates. Material United States federal income tax consequences and special considerations applicable to any such junior subordinated debentures will be described in the applicable prospectus supplement.

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        If a prospectus supplement specifies that the junior subordinated debentures will be denominated in a currency or currency unit other than U.S. dollars, the prospectus supplement shall also specify the denomination in which the junior subordinated debentures will be issued and the coin or currency in which the principal, premium, if any, and interest, if any, on the junior subordinated debentures will be payable, which may be U.S. dollars based upon the exchange rate for such other currency or currency unit existing on or about the time a payment is due.

        If any index is used to determine the amount of payments of principal of, premium, if any, or interest on any series of junior subordinated debentures, special U.S. federal income tax, accounting and other considerations will be described in the applicable prospectus supplement.

Additional Interest

        If, at any time a trust is required to pay any taxes, duties, assessments or governmental charges of whatever nature, other than withholding taxes, imposed by the United States, or any other taxing authority, then we will be required to pay additional interest on the junior subordinated debentures. The amount of any additional interest will be an amount sufficient so that the net amounts received and retained by the trust after paying any such taxes, duties, assessments or other governmental charges will be not less than the amounts that the trust would have received had no such taxes, duties, assessments or other governmental charges been imposed. This means that the trust will be in the same position it would have been in if it did not have to pay such taxes, duties, assessments or other charges.

Denominations, Registration and Transfer

        Unless otherwise indicated in the applicable prospectus supplement, we will issue the junior subordinated debentures in registered form only, without coupons. Junior subordinated debentures of any series will be exchangeable for other junior subordinated debentures of the same issue and series, of any authorized denominations, of a like principal amount, of the same original issue date and stated maturity and bearing the same interest rate.

        Junior subordinated debentures may be presented for exchange as provided above, and may be presented for registration of transfer at the office of the appropriate securities registrar or at the office of any transfer agent designated by us for such purposes. No service charge will be made for any transfer or exchange of the junior subordinated debentures. However, we or the debenture trustee may require a holder to pay an amount sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange. We will appoint the debenture trustee as securities registrar under the junior subordinated indenture. If the applicable prospectus supplement refers to any transfer agents, in addition to the securities registrar, initially designated by us with respect to any series of junior subordinated debentures, we may at any time rescind the designation of any such transfer agent or approve a change in the location through which any such transfer agent acts, provided that we maintain a transfer agent in each place of payment of such series. We may at any time designate additional transfer agents with respect to any series of junior subordinated debentures.

        In the event of any redemption, neither we nor the debenture trustee will be required to:

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Payment and Paying Agents

        Unless otherwise indicated in the applicable prospectus supplement, we will pay principal and any premium and interest on junior subordinated debentures (other than those in global form) at the office of the debenture trustee in the city of New York or at the office of any paying agent that we may designate from time to time.

        However, at our option, we may pay any interest by check mailed to the holders of registered junior subordinated debentures at their registered addresses or by transfer to an account maintained by a holder of registered junior subordinated debentures, as specified in the securities register. Unless otherwise indicated in the applicable prospectus supplement, payment of any interest on junior subordinated debentures will be made to the person in whose name the junior subordinated debentures are registered on the applicable record date, except in the case of defaulted interest. We may, at any time, designate additional paying agents or rescind the designation of any paying agent, provided that we at all times maintain a paying agent in each place of payment for each series of junior subordinated debentures.

        Any amounts deposited with the debenture trustee or any paying agent, or then held by us in trust, for the payment of the principal of any premium, if any, or interest on any junior subordinated debentures and remaining unclaimed for two years after such amounts have become due and payable shall, at our request, be repaid to us, and the holder of the junior subordinated debenture will be able to look only to us for payment, as a general unsecured creditor.

Option to Defer Interest Payments

        If provided in the applicable prospectus supplement, we will have the right from time to time during the term of any series of junior subordinated debentures to defer payment of interest for up to such number of consecutive interest payment periods as may be specified in the applicable prospectus supplement, subject to the terms, conditions and covenants, if any, specified in such prospectus supplement. Such deferral, however, may not extend beyond the stated maturity of such series of junior subordinated debentures. Certain U.S. federal income tax consequences and special considerations applicable to any such junior subordinated debentures will be described in the applicable prospectus supplement.

Redemption

        Unless otherwise indicated in the applicable prospectus supplement, the junior subordinated debentures will not be subject to any sinking fund.

        Unless otherwise indicated in the applicable prospectus supplement, we may, at our option and subject to receipt of prior approval by the Federal Reserve, if required, redeem the junior subordinated debentures of any series in whole at any time or in part from time to time. If the junior subordinated debentures of any series are so redeemable only on or after a specified date or upon the satisfaction of additional conditions, the applicable prospectus supplement will specify such date or describe such conditions. Except as otherwise specified in the applicable prospectus supplement, the redemption price for any junior subordinated debenture so redeemed will equal any accrued and unpaid interest thereon to the redemption date, plus 100% of the principal amount thereof.

        Except as otherwise specified in the applicable prospectus supplement, if a tax event (as defined below) in respect of a series of junior subordinated debentures or an investment company event or capital treatment event (each as defined below) shall occur and be continuing, we may, at our option and subject to receipt of prior approval by the Federal Reserve, if required, redeem such series of junior subordinated debentures in whole, but not in part, at any time within 90 days following of the occurrence of such tax event, investment company event or capital treatment event, at a redemption

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price equal to 100% of the principal amount of such junior subordinated debentures then outstanding plus accrued and unpaid interest to the date fixed for redemption, except as otherwise specified in the applicable prospectus supplement.

        Tax event means the receipt by the trust of an opinion of counsel experienced in such matters to the effect that, as a result of any amendment to, or change (including any announced proposed change) in, the laws (or any regulations thereunder) of the U.S. or any political subdivision or taxing authority thereof or therein, or as a result of any official administrative pronouncement or judicial decision interpreting or applying such laws or regulations, which amendment or change is effective or which proposed change, pronouncement or decision is announced on or after the date of issuance of such capital securities, there is more than an insubstantial risk that (i) the trust is, or will be within 90 days of the date of such opinion, subject to United States federal income tax with respect to income received or accrued on the corresponding series of corresponding junior subordinated debentures, (ii) interest payable by State Street on such series of corresponding junior subordinated debentures is not, or within 90 days of the date of such opinion, will not be, deductible by State Street, in whole or in part, for U.S. federal income tax purposes, or (iii) such trust is, or will be within 90 days of the date of such opinion, subject to more than a de minimis amount of other taxes, duties or other governmental charges.

        Investment company event means the receipt by the trust of an opinion of counsel experienced in such matters to the effect that, as a result of the occurrence of a change in law or regulation or a written change (including any announced prospective change) in interpretation or application of law or regulation by any legislative body, court, governmental agency or regulatory authority, there is more than an insubstantial risk that the trust is or will be considered an "investment company" that is required to be registered under the Investment Company Act of 1940, as amended, which change or prospective change becomes effective or would become effective, as the case may be, on or after the date of the issuance of the capital securities.

        Capital treatment event means our reasonable determination that, as a result of any amendment to, or change (including any proposed change) in, the laws (or any regulations thereunder) of the United States or any political subdivision thereof or therein, or as a result of any official or administrative pronouncement or action or judicial decision interpreting or applying such laws or regulations, which amendment or change is effective or which proposed change, pronouncement, action or decision is announced on or after the date of issuance of the applicable capital securities under the applicable trust agreement, there is more than an insubstantial risk that we will not be entitled to treat an amount equal to the liquidation amount of the applicable capital securities as "Tier I Capital" (or the then equivalent thereof) for purposes of the capital adequacy guidelines of the Federal Reserve, as then in effect and applicable to us.

        Notice of any redemption will be mailed at least 30 days, but not more than 60 days, before the redemption date to each holder of junior subordinated debentures to be redeemed at its registered address. Unless we default in payment of the redemption price, on and after the redemption date, interest will cease to accrue on such junior subordinated debentures or portions thereof called for redemption.

Restrictions on Certain Payments

        If junior subordinated debentures are issued to a trust or a trustee of a trust in connection with the issuance of trust securities by a trust and:

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        then:

Limitation on Mergers and Sales of Assets

        The junior subordinated indenture provides that we may not consolidate with, or merge into, any other corporation or convey or transfer our properties and assets substantially as an entirety unless:

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        The covenants contained in the indenture would not necessarily protect holders of the junior subordinated debentures in the event of a decline in credit quality resulting from takeovers, recapitalizations or similar restructurings.

Events of Default, Waiver and Notice

        The junior subordinated indenture provides that the following are events of default relating to the junior subordinated debentures:

        If an event of default (other than specified events of bankruptcy, insolvency or reorganization) under the junior subordinated indenture shall occur and be continuing, either the debenture trustee or the holders of not less than 25 percent in aggregate principal amount of the junior subordinated debentures of that series then outstanding may declare the principal of all junior subordinated debentures of that series to be due and payable immediately. If the holders of junior subordinated debentures fail to make such declaration, the holders of at least 25 percent in aggregate liquidation amount of the related capital securities shall have such right. If an event of default arising from specified events of bankruptcy, insolvency or reorganization shall occur, the principal amount of the junior subordinated debentures of that series then outstanding shall automatically become immediately due and payable.

        Under certain circumstances, the holders of a majority of the aggregate outstanding principal amount of that series of junior subordinated debentures may annul the declaration and waive the default. If the holders of junior subordinated debentures fail to annul such declaration and waive such default, the holders of a majority of the aggregate liquidation amount of the related capital securities shall have such right.

        The holders of a majority of the aggregate outstanding principal amount of that series of junior subordinated debentures may waive any default, except (i) a default in payment of principal or interest (unless such default has been cured and a sum sufficient to pay all matured installments of interest and principal due other than by acceleration has been deposited with the debenture trustee) or (ii) a default in respect of a covenant or provision that under the junior subordinated indenture cannot be modified or amended without the consent of the holder of each outstanding junior subordinated debenture. If the holders of junior subordinated debentures fail to waive such default, the holders of a majority of the aggregate liquidation amount of the related capital securities shall have such right.

        The holders of a majority of the principal amount of the junior subordinated debentures of any series affected shall have the right to direct the time, method and place of conducting any proceeding for any remedy available to the debenture trustee under the junior subordinated indenture.

        We are required to furnish to the debenture trustee annually a statement as to the performance of our obligations under the junior subordinated indenture and as to any default in such performance.

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        If a debenture event of default shall have occurred and be continuing, the property trustee will have the right to declare the principal of and the interest on the corresponding junior subordinated debentures, and any other amounts payable under the junior subordinated indenture, to be due and payable and to enforce its other rights as a creditor with respect to the corresponding junior subordinated debentures.

Distribution of the Junior Subordinated Debentures

        Under circumstances discussed more fully in the prospectus supplement involving the dissolution of a trust, provided that any required regulatory approval is obtained, junior subordinated debentures will be distributed to the holders of the trust securities in liquidation of that trust. See "Description of the Capital Securities—Liquidation Distribution Upon Dissolution."

        If the junior subordinated debentures are distributed to the holders of the capital securities, we will use our best efforts to have the junior subordinated debentures listed on the New York Stock Exchange or on such other national securities exchange or similar organization on which the capital securities are then listed or quoted.

Modification of Junior Subordinated Indenture

        From time to time we and the debenture trustee may, without the consent of the holders of the junior subordinated debentures, waive or supplement the junior subordinated indenture for specified purposes, including, among other things:

        We and the debenture trustee may make modifications and amendments to the indenture with the consent of the holders of a majority in principal amount of the junior subordinated debentures at the time outstanding. However, no such modification or amendment may, without the consent of the holder of each junior subordinated debenture affected thereby:

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        If the junior subordinated debentures are held by a trust or a trustee of a trust, no modification maybe made that adversely affects the holders of the related capital securities, and no termination of the junior subordinated indenture may occur, and no waiver of any event of default or compliance with any covenant will be effective without the prior consent of a majority in liquidation preference of trust securities of that trust. If the consent of the holder of each outstanding junior subordinated debenture is required, no modification shall be effective without the prior consent of each holder of related capital securities.

        In addition, we and the debenture trustee may execute, without the consent of any holder of junior subordinated debentures, any supplemental junior subordinated indenture for the purpose of creating any new series of junior subordinated debentures.

Enforcement of Certain Rights by Holders of Capital Securities

        If a debenture event of default with respect to a series of corresponding junior subordinated debentures has occurred and is continuing and such event of default is the result of our failure to pay interest or principal on the corresponding junior subordinated debentures when due, a holder of related capital securities may institute a legal proceeding directly against us for enforcement of payment to such holder of the principal of or interest on such corresponding junior subordinated debentures having a principal amount equal to the aggregate liquidation amount of the related capital securities. We may not amend the junior subordinated indenture to remove this right without the prior written consent of the holders of all of the capital securities outstanding. If such right is removed, the applicable trust may become subject to reporting obligations under the Exchange Act. We will have the right under the junior subordinated indenture to set off any payment made by us to such holder of capital securities in connection with any such direct action.

        The holders of the capital securities will not be able to exercise directly any remedies other than those set forth in the preceding paragraph unless there shall have been an event of default under the applicable trust agreement. Please see "Description of the Capital Securities—Events of Default; Notice."

Defeasance and Discharge

        The junior subordinated indenture provides that when:

then the junior subordinated indenture will cease to be of further effect (except as to our obligations to pay all other sums due under the junior subordinated indenture and to provide the officers' certificates

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and opinions of counsel described therein), and we will be deemed to have satisfied and discharged the junior subordinated indenture.

Conversion or Exchange

        The junior subordinated debentures may be convertible or exchangeable into junior subordinated debentures of another series or into capital securities of another series, on the terms provided in the applicable prospectus supplement. Such terms may include provisions for conversion or exchange, either mandatory, at the option of the holder, or at our option, in which case the number of shares of capital securities or other securities to be received by the holders of junior subordinated debentures would be calculated as of a time and in the manner stated in the applicable prospectus supplement.

Subordination

        The junior subordinated indenture contains a covenant by us that any junior subordinated debentures issued thereunder will be subordinate and junior in right of payment to all senior debt (as defined below) to the extent provided therein. If we make any payment or distribution of our assets upon any liquidation, dissolution, winding up, reorganization, assignment for the benefit of creditors, marshaling of assets or any bankruptcy, insolvency, debt restructuring or similar proceedings in connection with any insolvency or bankruptcy proceeding, the holders of senior debt will first be entitled to receive payment in full of principal of and premium and interest, if any, on such senior debt before the holders of junior subordinated debentures will be entitled to receive or retain any payment in respect of the principal of and premium and interest, if any, on the junior subordinated debentures. However, holders of senior debt will not be entitled to receive payment of any such amounts if the subordination provisions of such senior debt would require holders to pay such amounts over to the obligees on trade accounts payable or other liabilities arising in the ordinary course of our business.

        In the event of the acceleration of the maturity of any junior subordinated debentures, the holders of all senior debt outstanding at the time of such acceleration will first be entitled to receive payment in full of all amounts due thereon, including any amounts due upon acceleration, before the holders of the junior subordinated debentures will be entitled to receive or retain any payment in respect of the principal of or premium or interest, if any, on the junior subordinated debentures. However, the holders of senior debt will not be entitled to receive payment of any such amounts if the subordination provisions of such senior debt would require holders to pay such amounts over to the obligees on trade accounts payable or other liabilities arising in the ordinary course of State Street's business.

        No payments on account of principal or premium, if any, or interest in respect of the junior subordinated debentures may be made if there shall have occurred and be continuing a default in any payment with respect to senior debt or an event of default with respect to any senior debt resulting in the acceleration of the maturity thereof, or if any judicial proceedings are pending with respect to any such default.

        Debt means, with respect to any person, whether recourse is to all or a portion of the assets of such person and whether or not contingent:

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        Senior debt means the principal of and premium and interest, if any, including interest accruing on or after the filing of any petition in bankruptcy or for reorganization relating to us whether or not such claim for post-petition interest is allowed in such proceeding, on debt, whether incurred on or prior to the date of the junior subordinated indenture or thereafter incurred, unless, in the instrument creating or evidencing the same or pursuant to which the same is outstanding, it is provided that such obligations are not superior in right of payment to the junior subordinated debentures or to other debt that is equal or subordinated to the junior subordinated debentures, other than:

        The junior subordinated indenture places no limitation on the amount of senior debt that we may incur. We expect from time to time to incur additional indebtedness and other obligations constituting senior debt.

        The junior subordinated indenture provides that any of the subordination provisions described above that relate to any particular issue of junior subordinated debentures may be changed prior to such issuance. Any such change would be described in the applicable prospectus supplement.

Governing Law

        The junior subordinated indenture and the junior subordinated debentures will be governed by, and construed in accordance with, the internal laws of the State of New York.

The Debenture Trustee

        The debenture trustee will have all of the duties and responsibilities specified under the Trust Indenture Act. Subject to those provisions, the debenture trustee is under no obligation to exercise any of the powers vested in it by the junior subordinated indenture at the request of any holder of junior

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subordinated debentures unless offered reasonable indemnity by such holder against the costs, expenses and liabilities that might be incurred thereby. The debenture trustee is not required to expend or risk its own funds or otherwise incur personal financial liability in the performance of its duties if the debenture trustee reasonably believes that repayment or adequate indemnity is not reasonably assured it.

Corresponding Junior Subordinated Debentures

        State Street may issue one or more series of junior subordinated debentures under the junior subordinated indenture with terms corresponding to the terms of a series of related capital securities. In each such instance, concurrently with the issuance of each trust's capital securities, the trust will invest the proceeds thereof and the consideration paid by us for the common securities in the series of corresponding junior subordinated debentures issued by us to such trust. Each series of corresponding junior subordinated debentures will be in the principal amount equal to the aggregate stated liquidation amount of the related capital securities and the common securities of the trust and will rank equally with all other series of junior subordinated debentures. Holders of the related capital securities for a series of corresponding junior subordinated debentures will have the rights, in connection with modifications to the junior subordinated indenture or upon occurrence of debenture. events of default as described under "—Modification of Junior Subordinated Indenture," "—Events of Default, Waiver and Notice" and "—Enforcement of Certain Rights by Holders of Capital Securities."

        Unless otherwise specified in the applicable prospectus supplement, if a tax event relating to a trust shall occur and be continuing, we may, at our option and subject to prior approval of the Federal Reserve (if required), redeem the corresponding junior subordinated debentures at any time within 90 days of the occurrence of such tax event, in whole but not in part, subject to the provisions of the junior subordinated indenture and whether or not such corresponding junior subordinated debentures are then redeemable at our option. The redemption price for any corresponding junior subordinated debentures shall be equal to 100% of the principal amount of such corresponding junior subordinated debentures then outstanding plus accrued and unpaid interest to the date fixed for redemption. For so long as the applicable trust is the holder of all the outstanding corresponding junior subordinated debentures of such series, the proceeds of any such redemption will be used by the trust to redeem the corresponding trust securities in accordance with their terms. We may not redeem a series of corresponding junior subordinated debentures in part unless all accrued and unpaid interest has been paid in full on all outstanding corresponding junior subordinated debentures of such series for all interest proceeds terminating on or prior to the date of redemption.

        We will covenant, as to each series of corresponding junior subordinated debentures:

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DESCRIPTION OF THE CAPITAL SECURITIES

        The capital securities will be issued pursuant to the terms of an amended and restated trust agreement. The trust agreement will be qualified as an indenture under the Trust Indenture Act. The property trustee, J.P. Morgan Chase & Co., will act as trustee for the capital securities under the trust agreement for purposes of compliance with the provisions of the Trust Indenture Act. The terms of the capital securities will include those stated in the trust agreement and those made part of the trust agreement by the Trust Indenture Act.

        Set forth below is a summary of the material terms and provisions of the capital securities. This summary, which describes the material provisions of the capital securities, is not intended to be complete and is qualified by the trust agreement, the form of which is filed as an exhibit to the registration statement which contains this prospectus supplement, the Delaware Business Trust Act and the Trust Indenture Act.

General

        The declaration of trust authorizes the trustees to issue the trust securities on behalf of the trust. The trust securities represent undivided beneficial interests in the assets of the trust. We will own, directly or indirectly, all of the common securities. The common securities rank equally, and payments will be made on a pro rata basis, with the capital securities. However, if an event of default under a trust's trust agreement occurs and is continuing, the rights of the holders of the common securities to receive payments will be subordinated to the rights of the holders of the capital securities.

        The trust agreement does not permit the trust to issue any securities other than the trust securities or to incur any indebtedness. Under the trust agreement, the property trustee will own the junior subordinated debentures purchased by the trust for the benefit of the holders of the trust securities. Each guarantee agreement executed by us for the benefit of the holders of a trust's trust securities, each a guarantee, will be a guarantee on a subordinated basis with respect to the related trust securities but will not guarantee payment of distributions or amounts payable on redemption or liquidation of such trust securities when the related trust does not have funds on hand available to make such payments. Please see "Descriptions of the Capital Securities Guarantees."

Distributions

        Distributions on the capital securities:

        In the event that any date on which distributions are payable on the capital securities is not a business day, then payment of the distribution will be made on the next succeeding business day, and without any interest or other payment in respect to any such delay, except that, if such business day is in the next calendar year, payment of the distribution will be made on the immediately preceding business day. Each date on which distributions are payable in accordance with the foregoing is referred to as a distribution date. The term distribution includes any interest payable on unpaid distributions unless otherwise stated.

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        The amount of distributions payable for any period will be computed on the basis of a 360-day year of twelve 30-day months. The amount of distributions payable for any period shorter than a full quarterly period will be computed on the basis of the actual number of days elapsed per 30-day month. Distributions to which holders of capital securities are entitled will accumulate additional distributions at the rate per annum if and as specified in the applicable prospectus supplement.

        If provided in the applicable prospectus supplement, we have the right under the junior subordinated indenture, pursuant to which we will issue the corresponding junior subordinated debentures, to defer the payment of interest on any series of the corresponding junior subordinated debentures for up to a number of consecutive interest payment periods that will be specified in the prospectus supplement relating to such series (an extension period), provided that no extension period may extend beyond the stated maturity of the corresponding junior subordinated debentures.

        As a consequence of any such deferral, distributions on the related capital securities would be deferred, but would continue to accumulate additional distributions at the rate per annum, if any, set forth in the prospectus supplement for such capital securities, by the trust during any extension period. If we exercise our deferral right, then during any extension period, we may not:

        The revenue of each trust available for distribution to holders of its capital securities will be limited to payments under the corresponding junior subordinated debentures in which the trust will invest the proceeds from the issuance and sale of its trust securities. Please see "Description of Junior Subordinated Debentures—Corresponding Junior Subordinated Debentures." If we do not make interest payments on such corresponding junior subordinated debentures, the property trustee will not have funds available to pay distributions on the related capital securities. The payment of distributions, if and to the extent the trust has funds legally available for the payment of such distributions and cash

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sufficient to make such payments, is guaranteed by us on the basis set forth under "Description of the Capital Securities Guarantees."

        Distributions on the capital securities will be payable to the holders thereof as they appear on the register of such trust on the relevant record dates, which, as long as the capital securities remain in book-entry form, will be one business day prior to the relevant date of distribution. Subject to any applicable laws and regulations and the provisions of the applicable trust agreement, each such payment will be made as described under "Global Securities—Book-Entry Issuance." In the event any capital securities are not in book-entry form, the relevant record date for such capital securities shall be the date at least 15 days prior to the relevant date of distribution, as specified in the applicable prospectus supplement.

Redemption or Exchange

        Upon the repayment or redemption, in whole or in part, of any corresponding junior subordinated debentures, whether at maturity or upon earlier redemption as provided in the junior subordinated indenture, the property trustee shall apply the proceeds from such repayment or redemption to redeem a like amount (as defined below) of the trust securities, upon not less than 30 nor more than 60 days' notice, at a redemption price equal to the aggregate liquidation amount of such trust securities plus accumulated but unpaid distributions to the date of redemption and the related amount of the premium, if any, paid by us upon the concurrent redemption of such corresponding junior subordinated debentures. Please see "Description of Junior Subordinated Debentures—Redemption." If less than all of any series of corresponding junior subordinated debentures are to be repaid or redeemed on a redemption date, then the proceeds from such repayment or redemption will be allocated pro rata to the redemption of the related capital securities and the common securities. The amount of premium, if any, paid by us upon the redemption of all or any part of any series of any corresponding junior subordinated debentures to be repaid or redeemed on a redemption date shall be allocated pro rata to the redemption of the related capital securities and the common securities.

        We will have the right to redeem any series of corresponding junior subordinated debentures:


        If any tax event, investment company event or capital treatment event in respect of a series of capital securities and common securities shall occur and be continuing, then within 90 days of such occurrence we will have the right to redeem the corresponding junior subordinated debentures in whole, but not in part, and thereby cause a mandatory redemption of such capital securities and common securities in whole, but not in part, at the redemption price. In the event a tax event, investment company event or capital treatment event in respect of a series of capital securities and common securities has occurred and is continuing and we do not elect to redeem the corresponding junior subordinated debentures and thereby cause a mandatory redemption of such capital securities and common securities or to dissolve the related trust and cause the corresponding junior subordinated debentures to be distributed to holders of such capital securities and common securities in exchange therefor upon liquidation of the trust as described below, such capital securities will remain outstanding.

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        Like amount means:

        Liquidation amount means the stated amount per trust security as set forth in the applicable prospectus supplement.

Distribution of Corresponding Junior Subordinated Debentures

        We have the right at any time to dissolve any trust and, after satisfaction of the liabilities of creditors of such trust as provided by applicable law, cause such corresponding junior subordinated debentures in respect of the related capital securities and common securities issued by such trust to be distributed to the holders of such related capital securities and common securities in exchange for such trust securities. This may require the prior approval of the Federal Reserve Board.

        After the liquidation date fixed for any distribution of corresponding junior subordinated debentures for any series of capital securities:

        We cannot assure you as to the market prices for the capital securities or the corresponding junior subordinated debentures that may be distributed in exchange for capital securities if a dissolution and liquidation of a trust were to occur. Accordingly, the capital securities that an investor may purchase, or the corresponding junior subordinated debentures that the investor may receive on dissolution and liquidation of a trust, may trade at a discount to the price that the investor paid to purchase the capital securities.

Redemption Procedures

        Capital securities redeemed on each redemption date will be redeemed at the redemption price with the applicable proceeds from the contemporaneous redemption of the corresponding junior subordinated debentures. Redemptions of the capital securities shall be made and the redemption price shall be payable on each redemption date only to the extent that the related trust has funds on hand available for the payment of such redemption price. See also "—Subordination of Common Securities."

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        If a trust gives a notice of redemption of its capital securities, then, by 12:00 noon, New York City time, on the redemption date, to the extent funds are available, the property trustee will deposit irrevocably with DTC funds sufficient to pay the applicable redemption price and will give DTC irrevocable instructions and authority to pay the redemption price to the holders of such capital securities. Please see "Global Securities—Book-Entry Issuance." If such capital securities are no longer in book-entry form, the property trustee, to the extent funds are available, will irrevocably deposit with the paying agent for such capital securities funds sufficient to pay the applicable redemption price and will give such paying agent irrevocable instructions and authority to pay the redemption price to the holders thereof upon surrender of their certificates evidencing such capital securities.

        Notwithstanding the foregoing, distributions payable on or prior to the redemption date for any capital securities called for redemption will be payable to the holders of such capital securities on the relevant record dates for the related distribution dates. If notice of redemption shall have been given and funds deposited as required, then upon the date of such deposit:


        In the event that any date fixed for redemption of capital securities is not a business day, then payment of the redemption price will be made on the next succeeding business day, and without any interest or any other payment in respect of any such delay, except that, if such business day falls in the next calendar year, such payment will be made on the immediately preceding business day. In the event that payment of the redemption price in respect of capital securities called for redemption is improperly withheld or refused and not paid either by the trust or by us pursuant to the relevant guarantee as described under "Description of the Capital Securities Guarantees," distributions on such capital securities will continue to accrue at the then applicable rate, from the redemption date originally established by the trust for such capital securities to the date such redemption price is actually paid, in which case the actual payment date will be the date fixed for redemption for purposes of calculating the redemption price.

        Subject to applicable law (including, without limitation, U.S. federal securities law), we or our subsidiaries may at any time and from time to time purchase outstanding capital securities by tender, in the open market or by private agreement.

        Payment of the redemption price on the capital securities and any distribution of corresponding junior subordinated debentures to holders of capital securities will be made to the applicable recordholders as they appear on the register for such capital securities on the relevant record date. However, if any capital securities are not in book-entry form, the relevant record date for such capital securities will be a date at least 15 days prior to the redemption date or liquidation date, as applicable, as specified in the applicable prospectus supplement.

        If less than all of the capital securities and common securities issued by a trust are to be redeemed on a redemption date, then the aggregate liquidation amount of such capital securities and common securities to be redeemed shall be allocated pro rata to the capital securities and the common securities based upon the relative liquidation amounts of such classes. The property trustee will select the particular capital securities to be redeemed on a pro rata basis not more than 60 days prior to the redemption date from the outstanding capital securities not previously called for redemption, using any method that the property trustee deems fair and appropriate, including the selection for redemption of portions of the liquidation amount of capital securities in the minimum amounts that are specified in the applicable prospectus supplement. The property trustee shall promptly notify the trust registrar in writing of the capital securities selected for redemption and the liquidation amount to be redeemed.

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For all purposes of each trust agreement, unless the context otherwise requires, all provisions relating to the redemption of capital securities shall relate, in the case of any capital securities redeemed or to be redeemed only in part, to the portion of the aggregate liquidation amount of capital securities which has been or is to be redeemed.

        Notice of any redemption will be mailed at least 30 days but not more than 60 days before the redemption date to the registered address of each holder of trust securities to be redeemed.

Subordination of Common Securities

        Payment of distributions on, and the redemption price of, each trust's capital securities and common securities, as applicable, shall be made pro rata based on the liquidation amount of such capital securities and common securities. If, however, on any distribution date or redemption date a debenture event of default shall have occurred and be continuing, no payment of any distribution on, or redemption price of, any of the trust's common securities, and no other payment on account of the redemption, liquidation or other acquisition of such common securities, shall be made unless payment in full in cash of all accumulated and unpaid distributions on all of the trust's outstanding capital securities for all distribution periods terminating on or prior thereto, or in the case of payment of the redemption price the full amount of such redemption price on all of the trust's outstanding capital securities then called for redemption, shall have been made or provided for, and all funds available to the property trustee shall first be applied to the payment in full in cash of all distributions on, or redemption price of, the trust's capital securities then due and payable.

        In the case of any event of default under the applicable trust agreement resulting from a debenture event of default, we as holder of such trust's common securities, will be deemed to have waived any right to act with respect to any such event of default under the applicable trust agreement until the effect of all such events of default with respect to such capital securities have been cured, waived or otherwise eliminated. Until all events of default under the applicable trust agreement with respect to the capital securities have been so cured, waived or otherwise eliminated, the property trustee shall act solely on behalf of the holders of such capital securities and not on our behalf, and only the holders of such capital securities will have the right to direct the property trustee to act on their behalf.

Liquidation Distribution Upon Dissolution

        Pursuant to each trust agreement, each trust shall automatically dissolve upon expiration of its term and shall dissolve on the first to occur of:

        If an early dissolution occurs as described above, the trustees will liquidate the trust as expeditiously as possible by distributing, after satisfaction of liabilities to creditors of such trust as provided by applicable law, to the holders of such trust securities a like amount of the corresponding junior subordinated debentures. If the property trustee determines that such distribution is not practical, then the holders will be entitled to receive out of the assets of the trust available for

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distribution to holders, after satisfaction of liabilities to creditors of such trust as provided by applicable law, an amount equal to, in the case of holders of capital securities, the aggregate liquidation amount plus accrued and unpaid distributions to the date of payment (such amount being the liquidation distribution). If the trust has insufficient assets available to pay in full the aggregate liquidation distribution, then the amounts payable directly by such trust on its capital securities shall be paid on a pro rata basis. The holder(s) of such trust's common securities will be entitled to receive distributions upon any such liquidation pro rata with the holders of its capital securities, except that if a debenture event of default has occurred and is continuing, the capital securities shall have a priority over the common securities.

Events of Default; Notice

        Any one of the following events constitutes an event of default under the trust agreement of a trust (a trust event of default) regardless of the reason for such event of default and whether it shall be voluntary or involuntary or be effected by operation of law or pursuant to any judgment, decree or order of any court or any order, rule or regulation of any administrative or governmental body:

        Within the 90 days after the occurrence of any event of default actually known to the property trustee, the property trustee will transmit notice of such event of default to the holders of such trust's capital securities, the administrative trustees and to us, as depositor, unless such event of default shall have been cured or waived. We, as depositor, and the administrative trustees are required to file annually with the property trustee a certificate as to whether or not we or they are in compliance with all the conditions and covenants applicable to us and to them under each trust agreement.

        If a debenture event of default with respect to the corresponding junior subordinated debentures held by a trust has occurred and is continuing, the capital securities of such trust shall have a preference over such trust's common securities as described above. See "—Subordination of Common Securities" and "—Liquidation Distribution Upon Dissolution." The existence of an event of default does not entitle the holders of capital securities to accelerate the maturity of such securities.

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Removal of Trustees

        Unless a debenture event of default shall have occurred and be continuing, any trustee may be removed at any time by the holder of the common securities. If a debenture event of default has occurred and is continuing, the property trustee and the Delaware trustee may be removed by the holders of a majority in liquidation amount of the outstanding capital securities. In no event will the holders of the capital securities have the right to vote to appoint, remove or replace the administrative trustees, which voting rights are vested exclusively in us, as the holder of the common securities. No resignation or removal of a trustee and no appointment of a successor trustee shall be effective until the acceptance of appointment by the successor trustee in accordance with the provisions of the applicable trust agreement.

Co-Trustees and Separate Property Trustee

        Unless an event of default shall have occurred and be continuing, at any time or from time to time, for the purpose of meeting the legal requirements of the Trust Indenture Act or of any jurisdiction in which any part of the trust property may at the time be located, we, as the holder of the common securities, and the administrative trustees shall have the power to appoint one or more persons either to act as a co-trustee, jointly with the property trustee, of all or any part of such trust property, or to act as separate trustee of any such property, in either case with such powers as may be provided in the instrument of appointment, and to vest in such person or persons in such capacity any property, title, right or power deemed necessary or desirable, subject to the provisions of the applicable trust agreement. If a debenture event of default has occurred and is continuing, the property trustee alone shall have power to make such appointment.

Merger or Consolidation of Trustees

        Any person into which the property trustee, the Delaware trustee or any administrative trustee that is not a natural person may be merged or converted or with which it may be consolidated, or any person resulting from any merger, conversion or consolidation to which such trustee shall be a party, or any person succeeding to all or substantially all the corporate trust business of such trustee, shall be the successor of such trustee under each trust agreement, provided such person shall be otherwise qualified and eligible.

Mergers, Consolidations, Amalgamations or Replacements of the Trusts

        A trust may not merge with or into, consolidate, amalgamate, or be replaced by, or convey, transfer or lease its properties and assets substantially as an entirety to us or any other person, except as described below or as otherwise described in the trust agreement. A trust may, at our request, with the consent of the holders of at least a majority in liquidation amount of the capital securities and without the consent of the administrative trustees, the property trustee or the Delaware trustee, merge with or into, consolidate, amalgamate, or be replaced by, or convey, transfer or lease its properties and assets substantially as an entirety to, a trust organized as such under the laws of any state if:

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        Notwithstanding the foregoing, a trust may not, except with the consent of holders of 100% in liquidation amount of the capital securities, consolidate, amalgamate, merge with or into, or be replaced by or convey, transfer or lease its properties and assets substantially as an entirety to any other entity or permit any other entity to consolidate, amalgamate, merge with or into, or replace it if such consolidation, amalgamation, merger, replacement, conveyance, transfer or lease would cause the trust or the successor entity to be classified as other than a grantor trust for United States federal income tax purposes.

Voting Rights; Amendment of Each Trust Agreement

        Except as provided below and under "Description of the Capital Securities Guarantees—Amendments and Assignment" and as otherwise required by law and the applicable trust agreement, the holders of the capital securities will have no voting rights.

        We and the administrative trustees may amend each trust agreement without the consent of the holders of the capital securities, unless such amendment will materially and adversely affect the interests of any holder of capital securities:

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        Any such amendments will become effective when notice thereof is given to the holders of trust securities.

        We, the administrative trustees and the property trustee may amend each trust agreement with:

        Without the consent of each holder of trust securities, the trust agreement may not be amended to:

        So long as the property trustee holds any corresponding junior subordinated debentures, the trustees may not, without obtaining the prior approval of the holders of a majority in aggregate liquidation amount of all outstanding capital securities:

        If a consent under the junior subordinated indenture would require the consent of each holder of corresponding junior subordinated debentures affected thereby, no such consent may be given by the property trustee without the prior consent of each holder of the corresponding capital securities. The trustees may not revoke any action previously authorized or approved by a vote of the holders of the capital securities except by subsequent vote of the holders of the capital securities. The property trustee will notify each holder of the capital securities of any notice of default with respect to the corresponding junior subordinated debentures. In addition to obtaining the foregoing approvals of the holders of the capital securities, prior to taking any of the foregoing actions, the trustees will obtain an opinion of counsel experienced in such matters to the effect that such action would not cause the trust to be classified as other than a grantor trust for United States federal income tax purposes.

        Any required approval of holders of capital securities may be given at a meeting of holders of capital securities convened for such purpose or pursuant to written consent. The property trustee will cause a notice of any meeting at which holders of capital securities are entitled to vote, or of any

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matter upon which action by written consent of such holders is to be taken, to be given to each holder of record of capital securities in the manner set forth in each trust agreement.

        No vote or consent of the holders of capital securities will be required for a trust to redeem and cancel its capital securities in accordance with the applicable trust agreement.

        Notwithstanding that holders of capital securities are entitled to vote or consent under any of the circumstances described above, any of the capital securities that are owned by us or our affiliates or the trustees or any of their affiliates, shall, for purposes of such vote or consent, be treated as if they were not outstanding.

Payment and Paying Agency

        Payments on the capital securities shall be made to the depositary, which shall credit the relevant accounts at the depositary on the applicable distribution dates. If any trust's capital securities are not held by the depositary, such payments shall be made by check mailed to the address of the holder as such address shall appear on the register.

        Unless otherwise specified in the applicable prospectus supplement, the paying agent shall initially be the property trustee and any co-paying agent chosen by the property trustee and acceptable to us and to the administrative trustees. The paying agent shall be permitted to resign as paying agent upon 30 days' written notice to us and to the property trustee. In the event that the property trustee shall no longer be the paying agent, the administrative trustees will appoint a successor, which will be a bank or trust company acceptable to the administrative trustees and to us, to act as paying agent.

Registrar and Transfer Agent

        Unless otherwise specified in the applicable prospectus supplement, the property trustee will act as registrar and transfer agent for the capital securities.

        Registration of transfers of capital securities will be effected without charge by or on behalf of each trust, but upon payment of any tax or other governmental charges that may be imposed in connection with any transfer or exchange. The trusts will not be required to register or cause to be registered the transfer of their capital securities after such capital securities have been called for redemption.

Information Concerning the Property Trustee

        The property trustee, other than during the occurrence and continuance of an event of default, undertakes to perform only the duties that are specifically set forth in each trust agreement. After an event of default, the property trustee must exercise the same degree of care and skill as a prudent individual would exercise or use in the conduct of his or her own affairs. Subject to this provision, the property trustee is under no obligation to exercise any of the powers vested in it by the applicable trust agreement at the request of any holder of capital securities unless offered indemnity satisfactory to it by such holder against the costs, expenses and liabilities that might be incurred. If no event of default has occurred and is continuing and the property trustee is required to decide between alternative causes of action, construe ambiguous provisions in the applicable trust agreement or is unsure of the application of any provision of the applicable trust agreement, and the matter is not one on which holders of capital securities are entitled under such trust agreement to vote, then the property trustee will take any action that we direct. If we do not provide direction, the property trustee may take any action that it deems advisable and in the best interests of the holders of the trust securities and will have no liability except for its own bad faith, negligence or willful misconduct.

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Trust Expenses

        Pursuant to the trust agreement of each trust, we, as depositor, agree to pay:

Governing Law

        Each trust agreement will be governed by and construed in accordance with the laws of Delaware.

Miscellaneous

        The administrative trustees are authorized and directed to conduct the affairs of and to operate the trusts in such a way that no trust will be required to register as an investment company under the Investment Company Act or characterized as other than a grantor trust for United States federal income tax purposes. The administrative trustees are authorized and directed to conduct their affairs so that the corresponding junior subordinated debentures will be treated as indebtedness of State Street for United States federal income tax purposes. In this connection, we and the administrative trustees are authorized to take any action, not inconsistent with applicable law, the certificate of trust of each trust or each trust agreement, that we and the administrative trustees determine to be necessary or desirable to achieve such end, as long as such action does not materially and adversely affect the interests of the holders of the related capital securities.

        Holders of the capital securities have no preemptive or similar rights.

        No trust may borrow money or issue debt or mortgage or pledge any of its assets.


COMMON SECURITIES

        In connection with the issuance of capital securities, each trust will issue one series of common securities having the terms, including distributions, redemption, voting and liquidation rights, set forth in the applicable prospectus supplement. Except for voting rights, the terms of the common securities will be substantially identical to the terms of the capital securities. The common securities will rank equally, and payments will be made on the common securities pro rata, with the capital securities, except that, upon an event of default, the rights of the holders of the common securities to payment in respect of distributions and payments upon liquidation, redemption and otherwise will be subordinated to the rights of the holders of the capital securities. Except in limited circumstances, the common securities of a trust carry the right to vote to appoint, remove or replace any of the trustees of that trust. We will own, directly or indirectly, all of the common securities of each trust.


DESCRIPTION OF THE CAPITAL SECURITIES GUARANTEES

        Set forth below is a summary of information concerning the capital securities guarantees that we will execute and deliver for the benefit of the holders of capital securities. Each capital securities guarantee will be qualified as an indenture under the Trust Indenture Act. J.P. Morgan Chase & Co. will act as the guarantee trustee for purposes of the Trust Indenture Act. The terms of each capital securities guarantee will be those set forth in the capital securities guarantee and those made part of the capital securities guarantee by the Trust Indenture Act. The summary of the material terms of the capital securities guarantees is not intended to be complete and is qualified in all respects by the

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provisions of the form of capital securities guarantee which is filed as an exhibit to the registration statement which contains this prospectus, and the Trust Indenture Act. The guarantee trustee will hold each capital securities guarantee for the benefit of the holders of the capital securities of the applicable trust.

General

        Pursuant to and to the extent set forth in the capital securities guarantee, we will irrevocably and unconditionally agree to pay in full to the holders of the trust securities, except to the extent paid by the trust, as and when due, regardless of any defense, right of set-off or counterclaim which the trust may have or assert, the following payments, which are referred to as guarantee payments, without duplication:

        The redemption price and liquidation amount will be fixed at the time the capital securities are issued.

        Our obligation to make a guarantee payment may be satisfied by direct payment of the required amounts to the holders of capital securities or by causing the trust to pay such amounts to such holders.

        The capital securities guarantees will not apply to any payment of distributions except to the extent a trust shall have funds available for such payments. If we do not make interest payments on the junior subordinated debentures purchased by a trust, the trust will not pay distributions on the capital securities and will not have funds available for such payments. Please see "—Status of the Guarantees." Because we are a holding company, our rights to participate in the assets of any of our subsidiaries upon the subsidiary's liquidation or reorganization will be subject to the prior claims of the subsidiary's creditors except to the extent that we may ourselves be a creditor with recognized claims against the subsidiary. Except as otherwise provided in the applicable prospectus supplement, the capital securities guarantees do not limit the incurrence or issuance by us of other secured or unsecured debt.

        The capital securities guarantees, when taken together with our obligations under the junior subordinated debentures, the indentures and the trust agreements, including our obligations to pay costs, expenses, debts and liabilities of the trusts, other than those relating to trust securities, will provide a full and unconditional guarantee on a subordinated basis of payments due on the capital securities.

        We have also agreed separately to irrevocably and unconditionally guarantee the obligations of the trusts with respect to the common securities to the same extent as the capital securities guarantees, except that upon an event of default under the indenture, holders of capital securities shall have

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priority over holders of common securities with respect to distributions and payments on liquidation, redemption or otherwise.

Status of the Guarantees

        Each capital security guarantee will be unsecured and will rank:

        Each capital securities guarantee will constitute a guarantee of payment and not of collection. This means that the guaranteed party may sue the guarantor to enforce its rights under the guarantee without suing any other person or entity. Each capital securities guarantee will be held for the benefit of the holders of the related trust securities and will be discharged only by payment of the guarantee payments in full to the extent not paid by the trust or upon the junior subordinated debentures.

Amendments and Assignment

        The capital securities guarantee may be amended only with the prior approval of the holders of not less than a majority in aggregate liquidation amount of the outstanding capital securities. No vote will be required, however, for any changes that do not adversely affect the rights of holders of capital securities. All guarantees and agreements contained in the capital securities guarantee will bind our successors, assignees, receivers, trustees and representatives and will be for the benefit of the holders of the capital securities then outstanding.

Termination of the Guarantees

        Each capital securities guarantee will terminate upon full payment of the redemption price of all capital securities, upon distribution of the junior subordinated debentures to the holders of the trust securities or upon full payment of the amounts payable in accordance with the trust agreement upon liquidation of such trust. Each capital securities guarantee will continue to be effective or will be reinstated, as the case may be, if at any time any holder of capital securities must restore payment of any sums paid under the capital securities or the capital securities guarantee.

Events of Default

        An event of default under a capital securities guarantee will occur if we fail to perform any payment or other obligations under the capital securities guarantee.

        The holders of a majority in liquidation amount of the capital securities have the right to direct the time, method and place of conducting any proceeding for any remedy available to the guarantee trustee in respect of the capital securities guarantee or to direct the exercise of any trust or power conferred upon the guarantee trustee under the capital securities guarantee. Any holder of capital securities may institute a legal proceeding directly against us to enforce the guarantee trustee's rights and our obligations under the capital securities guarantee, without first instituting a legal proceeding against the relevant trust, the guarantee trustee or any other person or entity.

        As guarantor, we are required to file annually with the guarantee trustee a certificate as to whether or not we are in compliance with all applicable conditions and covenants applicable under the capital securities guarantee.

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Information Concerning the Guarantee Trustee

        Prior to the occurrence of a default relating to a capital securities guarantee, the guarantee trustee is required to perform only the duties that are specifically set forth in the capital securities guarantee. Following the occurrence of a default, the guarantee trustee will exercise the same degree of care as a prudent individual would exercise in the conduct of his or her own affairs. If the foregoing requirements have been met, the guarantee trustee is under no obligation to exercise any of the powers vested in it by a capital securities guarantee at the request of any holder of capital securities, unless offered indemnity satisfactory to it against the costs, expenses and liabilities which might be incurred thereby.

        We and our affiliates maintain certain accounts and other banking relationships with the guarantee trustee and its affiliates in the ordinary course of business.

Governing Law

        The capital securities guarantees will be governed by and construed in accordance with the internal laws of the State of New York.


RELATIONSHIP AMONG THE CAPITAL SECURITIES, THE CORRESPONDING JUNIOR
SUBORDINATED DEBENTURES AND THE CAPITAL SECURITIES GUARANTEES

        As set forth in the trust agreements, the sole purpose of the trusts is to issue the trust securities and to invest the proceeds in the junior subordinated debentures.

        As long as payments of interest and other payments are made when due on the junior subordinated debentures, those payments will be sufficient to cover the distributions and payments due on the trust securities. This is due to the following factors:

        To the extent that funds are available, we guarantee payments of distributions and other payments due on the capital securities to the extent described in this prospectus. If we do not make interest payments on the junior subordinated debentures, the trust will not have sufficient funds to pay distributions on the capital securities. Each capital securities guarantee is a subordinated guarantee in relation to the capital securities. The capital securities guarantee does not apply to any payment of distributions unless and until the trust has sufficient funds for the payment of such distributions. Please see "Description of the Capital Securities Guarantees."

        We have the right to set off any payment that we are otherwise required to make under the junior subordinated indenture with any payment that we have previously made or are concurrently on the date of such payment making under a related guarantee.

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        The capital securities guarantees cover the payment of distributions and other payments on the capital securities only if and to the extent that we have made a payment of interest or principal or other payments on the junior subordinated debentures. The capital securities guarantees, when taken together with our obligations under the junior subordinated debentures and the indenture and our obligations under the trust agreement, will provide a full and unconditional guarantee of distributions, redemption payments and liquidation payments on the capital securities.

        If we fail to make interest or other payments on the junior subordinated debentures when due, taking account of any extension period, the trust agreements allow the holders of the capital securities to direct the property trustee to enforce its rights under the junior subordinated debentures. If the property trustee fails to enforce these rights, any holder of capital securities may directly sue us to enforce such rights without first suing the property trustee or any other person or entity.

        A holder of capital securities may institute a direct action if a trust agreement event of default has occurred and is continuing and such event is attributable to our failure to pay interest or principal on the junior subordinated debentures when due. A direct action may be brought without first (1) directing the property trustee to enforce the terms of the junior subordinated debentures or (2) suing us to enforce the property trustee's rights under the junior subordinated debentures. In connection with such direct action, we will be subrogated to the rights of such holder of capital securities under the trust agreement to the extent of any payment made by us to such holder of capital securities. Consequently, we will be entitled to payment of amounts that a holder of capital securities receives in respect of an unpaid distribution to the extent that such holder receives or has already received full payment relating to such unpaid distribution from a trust.

        We acknowledge that the guarantee trustee will enforce the capital securities guarantees on behalf of the holders of the capital securities. If we fail to make payments under the capital securities guarantees, the holders of the capital securities may direct the guarantee trustee to enforce its rights thereunder. If the guarantee trustee fails to enforce the capital securities guarantees, any holder of capital securities may directly sue us to enforce the guarantee trustee's rights under the capital securities guarantees. Such holder need not first sue the trust, the guarantee trustee, or any other person or entity. A holder of capital securities may also directly sue us to enforce such holder's right to receive payment under the capital securities guarantees. Such holder need not first (1) direct the guarantee trustee to enforce the terms of the capital securities guarantee or (2) sue the trust or any other person or entity.

        A default or event of default under any of our senior debt would not constitute a default or event of default under the junior subordinated indenture. However, in the event of payment defaults under, or acceleration of, our senior debt, the subordination provisions of the junior subordinated indenture provide that no payments may be made in respect of the corresponding junior subordinated debentures until such senior debt has been paid in full or any payment default thereunder has been cured or waived. Failure to make required payments on any series of corresponding junior subordinated debentures would constitute an event of default under the junior subordinated indenture.

        We and the trusts believe that the above mechanisms and obligations, taken together, are equivalent to a full and unconditional guarantee by us of payments due on the capital securities. Please see "Description of the Capital Securities Guarantees—General."

Limited Purpose of Trusts

        Each trust's capital securities evidence a beneficial interest in such trust, and each trust exists for the sole purpose of issuing its capital securities and common securities and investing the proceeds in corresponding junior subordinated debentures. A principal difference between the rights of a holder of a capital security and a holder of a corresponding junior subordinated debenture is that a holder of a corresponding junior subordinated debenture is entitled to receive from us the principal amount of and

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interest accrued on corresponding junior subordinated debentures held, while a holder of capital securities is entitled to receive distributions from such trust (or from us under the applicable guarantee) if and to the extent such trust has funds available for the payment of such distributions.

Rights Upon Dissolution

        Upon any voluntary or involuntary dissolution, winding up or liquidation of any trust involving the liquidation of the corresponding junior subordinated debentures, after satisfaction of liabilities to creditors of the trust, the holders of the related capital securities will be entitled to receive, out of the assets held by such trust, the liquidation distribution in cash. Please see "Description of the Capital Securities—Liquidation Distribution Upon Dissolution." Upon any voluntary or involuntary liquidation or bankruptcy of State Street, the property trustee, as holder of the corresponding junior subordinated debentures, would be a subordinated creditor of State Street, subordinated in right of payment to all senior debt as set forth in the junior subordinated indenture, but entitled to receive payment in full of principal and interest before any of our stockholders receive distributions. Since we are the guarantor under each guarantee and have agreed to pay for all costs, expenses and liabilities of each trust, other than the trusts' obligations to the holders of its capital securities, the positions of a holder of such capital securities and a holder of such corresponding junior subordinated debentures relative to other creditors and to our stockholders in the event of liquidation or bankruptcy are expected to be substantially the same.


DESCRIPTION OF PREFERRED STOCK

        The following summary contains a description of the general terms of the preferred stock that we may issue. Other terms of any series of preferred stock will be described in the prospectus supplement relating to that series of preferred stock. The terms of any series of preferred stock may differ from the terms described below. Certain provisions of the preferred stock described below and in any prospectus supplement are not complete. You should refer to our Restated Articles of Organization, as amended, and the certificate of designation which will be filed with the SEC in connection with the offering of the series of preferred stock.

General

        Our articles of organization permit our board of directors to authorize the issuance of up to 3,500,000 shares of preferred stock, without par value, in one or more series, without shareholder action. The board of directors can determine the rights, preferences and limitations of each series. Therefore, without shareholder approval, our board of directors can authorize the issuance of preferred stock with voting, conversion and other rights that could dilute the voting power and other rights of our common stockholders. None of our preferred stock is currently outstanding.

        The preferred stock has the terms described below unless otherwise provided in the prospectus supplement relating to a particular series of the preferred stock. You should read the prospectus supplement relating to the particular series of the preferred stock being offered for specific terms, including:

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        The preferred stock will, when issued, be fully paid and nonassessable. Unless otherwise specified in the prospectus supplement, each series of the preferred stock will rank equally as to dividends and liquidation rights in all respects with each other series of preferred stock. The rights of holders of shares of each series of preferred stock will be subordinate to those of our general creditors.

        As described under "Description of Depositary Shares," we may, at our option, with respect to any series of the preferred stock, elect to offer fractional interests in shares of preferred stock, and provide for the issuance of depositary receipts representing depositary shares, each of which will represent a fractional interest in a share of the series of the preferred stock. The fractional interest will be specified in the prospectus supplement relating to a particular series of the preferred stock.

Rank

        Any series of the preferred stock will, with respect to the priority of the payment of dividends and the priority of payments upon liquidation, winding up and dissolution, rank:

Dividends

        Holders of the preferred stock of each series will be entitled to receive, when, as and if declared by our board of directors, cash dividends at such rates and on such dates described in the prospectus supplement. Different series of preferred stock may be entitled to dividends at different rates or based on different methods of calculation. The dividend rate may be fixed or variable or both. Dividends will be payable to the holders of record as they appear on our stock books on record dates fixed by our board of directors, as specified in the applicable prospectus supplement.

        Dividends on any series of the preferred stock may be cumulative or noncumulative, as described in the applicable prospectus supplement. If our board of directors does not declare a dividend payable on a dividend payment date on any series of noncumulative preferred stock, then the holders of that noncumulative preferred stock will have no right to receive a dividend for that dividend payment date, and we will have no obligation to pay the dividend accrued for that period, whether or not dividends on that series are declared payable on any future dividend payment dates. Dividends on any series of cumulative preferred stock will accrue from the date we initially issue shares of such series or such other date specified in the applicable prospectus supplement.

        No full dividends may be declared or paid or funds set apart for the payment of any dividends on any parity securities unless dividends have been paid or set apart for payment on the preferred stock. If full dividends are not paid, the preferred stock will share dividends pro rata with the parity securities. No dividends may be declared or paid or funds set apart for the payment of dividends on any junior

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securities unless full cumulative dividends for all dividend periods terminating on or prior to the date of the declaration or payment will have been paid or declared and a sum sufficient for the payment set apart for payment on the preferred stock.

        Our ability to pay dividends on our preferred stock is subject to policies established by the Federal Reserve Board.

Rights Upon Liquidation

        If we dissolve, liquidate or wind up our affairs, either voluntarily or involuntarily, the holders of each series of preferred stock will be entitled to receive, before any payment or distribution of assets is made to holders of junior securities, liquidating distributions in the amount described in the prospectus supplement relating to that series of the preferred stock, plus an amount equal to accrued and unpaid dividends and, if the series of the preferred stock is cumulative, for all dividend periods prior to that point in time. If the amounts payable with respect to the preferred stock of any series and any other parity securities are not paid in full, the holders of the preferred stock of that series and of the parity securities will share proportionately in the distribution of our assets in proportion to the full liquidation preferences to which they are entitled. After the holders of preferred stock and the parity securities are paid in full, they will have no right or claim to any of our remaining assets.

        Because we are a bank holding company, our rights, the rights of our creditors and of our stockholders, including the holders of the preferred stock offered by this prospectus, to participate in the assets of any subsidiary upon the subsidiary's liquidation or recapitalization may be subject to the prior claims of the subsidiary's creditors except to the extent that we may ourselves be a creditor with recognized claims against the subsidiary.

Redemption

        A series of the preferred stock may be redeemable, in whole or in part, at our option with prior Federal Reserve Board approval. In addition, a series of preferred stock may be subject to mandatory redemption pursuant to a sinking fund or otherwise. The redemption provisions that may apply to a series of preferred stock, including the redemption dates and the redemption prices for that series, will be described in the prospectus supplement.

        In the event of partial redemptions of preferred stock, whether by mandatory or optional redemption, our board of directors will determine the method for selecting the shares to be redeemed, which may be by lot or pro rata or by any other method determined to be equitable.

        On or after a redemption date, unless we default in the payment of the redemption price, dividends will cease to accrue on shares of preferred stock called for redemption. In addition, all rights of holders of the shares will terminate except for the right to receive the redemption price.

        Unless otherwise specified in the applicable prospectus supplement for any series of preferred stock, if any dividends on any other series of preferred stock ranking equally as to payment of dividends and liquidation rights with such series of preferred stock are in arrears, no shares of any such series of preferred stock may be redeemed, whether by mandatory or optional redemption, unless all shares of preferred stock are redeemed, and we will not purchase any shares of such series of preferred stock. This requirement, however, will not prevent us from acquiring such shares pursuant to a purchase or exchange offer made on the same terms to holders of all such shares outstanding.

        Under current regulations, bank holding companies, except in certain narrowly defined circumstances, may not exercise any option to redeem shares of preferred stock included as Tier 1 capital without the prior approval of the Federal Reserve Board. Ordinarily, the Federal Reserve Board would not permit such a redemption unless (1) the shares are redeemed with the proceeds of a sale by the bank holding company of common stock or perpetual preferred stock or (2) the Federal Reserve

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determines that the bank holding company's condition and circumstances warrant the reduction of a source of permanent capital.

Voting Rights

        Unless otherwise described in the applicable prospectus supplement, holders of the preferred stock will have no voting rights except as set forth below or as otherwise required by law or in our articles of organization.

        Under regulations adopted by the Federal Reserve Board, if the holders of any series of the preferred stock are or become entitled to vote for the election of directors, such series may then be deemed a "class of voting securities" and a holder of 25% or more of such series, or a holder of 5% or more if it otherwise exercises a "controlling influence" over us, may then be subject to regulation as a bank holding company in accordance with the Bank Holding Company Act. In addition, at such time as such series is deemed a class of voting securities, (a) any other bank holding company may be required to obtain the approval of the Federal Reserve Board to acquire or retain 5% or more of that series and (b) any person other than a bank holding company may be required to obtain the approval of the Federal Reserve Board to acquire or retain 10% or more of that series.

Exchangeability

        The holders of shares of preferred stock of any series may be required at any time or at maturity to exchange those shares for our debt securities. The applicable prospectus supplement will specify the terms of any such exchange.

Transfer Agent and Registrar

        Unless otherwise indicated in the applicable prospectus supplement, Computershare, an affiliate of State Street, will be the transfer agent, dividend and redemption price disbursement agent and registrar for shares of each series of the preferred stock.


DESCRIPTION OF DEPOSITARY SHARES

General

        We may, at our option, elect to offer fractional shares of preferred stock, which we call depositary shares, rather than full shares of preferred stock. If we do, we will issue to the public receipts, called depositary receipts, for depositary shares, each of which will represent a fraction, to be described in the prospectus supplement, of a share of a particular series of preferred stock.

        The shares of any series of preferred stock represented by depositary shares will be deposited with a depositary named in the prospectus supplement. Unless otherwise provided in the prospectus supplement, each owner of a depositary share will be entitled, in proportion to the applicable fractional interest in a share of preferred stock represented by the depositary share, to all the rights and preferences of the preferred stock represented by the depositary share. Those rights include dividend, voting, redemption, conversion and liquidation rights.

Dividends and Other Distributions

        The depositary will distribute all cash dividends or other cash distributions received in respect of the preferred stock to the record holders of depositary shares in proportion to the numbers of depositary shares owned by those holders.

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        If there is a distribution other than in cash, the depositary will distribute property received by it to the record holders of depositary shares, unless the depositary determines that it is not feasible to make the distribution. If this occurs, the depositary may, with our approval, sell the property and distribute the net proceeds from the sale to the holders.

Withdrawal of Stock

        Unless the related depositary shares have been previously called for redemption, upon surrender of the depositary receipts at the office of the depositary, the holder of the depositary shares will be entitled to delivery, at the office of the depositary to or upon his or her order, of the number of whole shares of the preferred stock and any money or other property represented by the depositary shares. If the depositary receipts delivered by the holder evidence a number of depositary shares in excess of the number of depositary shares representing the number of whole shares of preferred stock to be withdrawn, the depositary will deliver to the holder at the same time a new depositary receipt evidencing the excess number of depositary shares. In no event will the depositary deliver fractional shares of preferred stock upon surrender of depositary receipts.

Redemption of Depositary Shares

        Whenever we redeem shares of preferred stock held by the depositary, the depositary will redeem as of the same redemption date the number of depositary shares representing shares of the preferred stock so redeemed, so long as we have paid in full to the depositary the redemption price of the preferred stock to be redeemed plus an amount equal to any accumulated and unpaid dividends on the preferred stock to the date fixed for redemption. The redemption price per depositary share will be equal to the redemption price and any other amounts per share payable on the preferred stock multiplied by the fraction of a share of preferred stock represented by one depositary share. If less than all the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by lot or pro rata or by any other equitable method as may be determined by the depositary.

        After the date fixed for redemption, depositary shares called for redemption will no longer be deemed to be outstanding and all rights of the holders of depositary shares will cease, except the right to receive the moneys payable upon redemption and any money or other property to which the holders of the depositary shares were entitled upon redemption upon surrender to the depositary of the depositary receipts evidencing the depositary shares.

Voting the Preferred Stock

        Upon receipt of notice of any meeting at which the holders of the preferred stock are entitled to vote, the depositary will mail the information contained in the notice of meeting to the record holders of the depositary receipts relating to that preferred stock. The record date for the depositary receipts relating to the preferred stock will be the same date as the record date for the preferred stock. Each record holder of the depositary shares on the record date will be entitled to instruct the depositary as to the exercise of the voting rights pertaining to the number of shares of preferred stock represented by that holder's depositary shares. The depositary will endeavor, insofar as practicable, to vote the number of shares of preferred stock represented by the depositary shares in accordance with those instructions, and we will agree to take all action which may be deemed necessary by the depositary in order to enable the depositary to do so. The depositary will not vote any shares of preferred stock except to the extent it receives specific instructions from the holders of depositary shares representing that number of shares of preferred stock.

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Charges of Depositary

        We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangements. We will pay charges of the depositary in connection with the initial deposit of the preferred stock and any redemption of the preferred stock. Holders of depositary receipts will pay other transfer and other taxes and governmental charges and such other charges as are expressly provided in the deposit agreement to be for their accounts.

Resignation and Removal of Depositary

        The depositary may resign at any time by delivering to us notice of its election to do so, and we may remove the depositary at any time. Any resignation or removal of the depositary will take effect upon our appointment of a successor depositary and its acceptance of such appointment. The successor depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50,000,000.

Notices

        The depositary will forward to holders of depositary receipts all notices, reports and other communications, including proxy solicitation materials received from us, which are delivered to the depositary and which we are required to furnish to the holders of the preferred stock.

Limitation of Liability

        Neither we nor the depositary will be liable if either of us is prevented or delayed by law or any circumstance beyond our control in performing our obligations. Our obligations and those of the depositary will be limited to performance in good faith of our and their duties thereunder. We and the depositary will not be obligated to prosecute or defend any legal proceeding in respect of any depositary shares or preferred stock unless satisfactory indemnity is furnished. We and the depositary may rely upon written advice of counsel or accountants, on information provided by persons presenting preferred stock for deposit, holders of depositary receipts or other persons believed to be competent and on documents believed to be genuine.

Inspection of Books

        Any record holder of depositary shares who has been a holder for at least six months or who holds at least five percent of our outstanding shares of capital stock will be entitled to inspect the transfer books relating to the depositary shares and the list of record holders of depositary shares upon certification to the depositary that the holder is acting in good faith and that the inspection is for a proper purpose.


DESCRIPTION OF COMMON STOCK

General

        We have 500,000,000 shares of authorized common stock, $1.00 par value per share, of which 335,192,584 shares were outstanding as of January 31, 2006.

        Holders of our common stock are entitled to receive dividends when, as and if declared by our board of directors out of any funds legally available for dividends. Holders of our common stock are also entitled, upon our liquidation, and after claims of creditors and preferences of preferred stock, and any other class or series of preferred stock outstanding at the time of liquidation, to receive pro rata our net assets. We pay dividends on our common stock only if we have paid or provided for all

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dividends on our outstanding series of preferred stock, for the then current period and, in the case of any cumulative preferred stock, all prior periods.

        Our preferred stock has, or upon issuance will have, preference over our common stock with respect to the payment of dividends and the distribution of assets in the event of our liquidation or dissolution. Our preferred stock also has such other preferences as may be fixed by our board of directors.

        Holders of our common stock are entitled to one vote for each share that they hold and are vested with all of the voting power except as our board of directors has provided, or may provide in the future, with respect to preferred stock or any other class or series of preferred stock that the board of directors may hereafter authorize. See "Description of Preferred Stock." Shares of our common stock are not redeemable, and have no subscription, conversion or preemptive rights.

        Our common stock is listed on the New York Stock Exchange, the Boston Stock Exchange and the Archipelago Stock Exchange. Outstanding shares of our common stock are validly issued, fully paid and non-assessable. Holders of our common stock are not, and will not be, subject to any liability as stockholders.

Shareholders' Rights Plan

        In 1988, State Street declared a dividend of one preferred share purchase right for each outstanding share of common stock pursuant to a Shareholders' Rights Agreement. On June 18, 1998, State Street adopted an amendment to the Rights Agreement and has restated the Rights Agreement. Under the Amended and Restated Rights Agreement, a right may be exercised, under certain conditions, to purchase one four-hundredths share of a series of participating preferred stock at an exercise price of $265, subject to adjustment. The rights become exercisable if a party acquires or obtains the right to acquire 10% or more of State Street's common stock or after commencement or public announcement of an offer for 10% or more of State Street's common stock. When exercisable, under certain conditions, each right also entitles the holder thereof to purchase shares of common stock, of either State Street or of the acquiror, having a market value of two times the then current exercise price of that right.

        The rights expire in September 2008, and may be redeemed at a price of $.0025 per right at any time prior to expiration or the acquisition of 10% of State Street's common stock. Under certain circumstances, the rights may be redeemed after they become exercisable and may be subject to automatic redemption.

        The Rights Agreement may have the effect of delaying, deferring or preventing a change in control of State Street Corporation.

Transfer Agent and Registrar

        The transfer agent and registrar for our common stock is Computershare, an affiliate of State Street.

Restrictions on Ownership

        The Bank Holding Company Act requires any "bank holding company," as defined in the Bank Holding Company Act, to obtain the approval of the Federal Reserve Board prior to the acquisition of 5% or more of our common stock. Any person, other than a bank holding company, is required to obtain prior approval of the Federal Reserve Board to acquire 10% or more of our common stock under the Change in Bank Control Act. Any holder of 25% or more of our common stock, or a holder of 5% or more if such holder otherwise exercises a "controlling influence" over us, is subject to regulation as a bank holding company under the Bank Holding Company Act. Chapter 167A of the

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General Laws of Massachusetts requires any "bank holding company," as defined in Chapter 167A, to obtain prior approval of the board of bank incorporation before (i) acquiring 5% or more of our common stock, (ii) acquiring all or substantially all of our assets or (iii) merging or consolidating with us.


DESCRIPTION OF STOCK PURCHASE CONTRACTS AND STOCK PURCHASE UNITS

        We may issue stock purchase contracts, including contracts obligating holders to purchase from or sell to us, and us to sell to or purchase from the holders, a specified number of shares of our common stock, preferred stock or depositary shares at a future date or dates. The price per share of common stock, preferred stock or depositary shares and the number of shares of each may be fixed at the time the stock purchase contracts are issued or may be determined by reference to a specific formula set forth in the stock purchase contracts. The stock purchase contracts may be issued separately or as part of units, often known as stock purchase units, consisting of one or more stock purchase contracts and beneficial interests in:

securing the holders' obligations to purchase the common stock, preferred stock or depositary shares under the stock purchase contracts. The stock purchase contracts may require us to make periodic payments to the holders of the stock purchase units or vice versa, and these payments may be unsecured or prefunded on some basis. The stock purchase contracts may require holders to secure their obligations under those contracts in a specified manner, including without limitation by pledging their interest in another stock purchase contract.

        The applicable prospectus supplement will describe the terms of the stock purchase contracts and stock purchase units, including, if applicable, collateral or depositary arrangements.


DESCRIPTION OF WARRANTS

        We may issue warrants to purchase debt securities, preferred stock, depositary shares or common stock. We may offer warrants separately or together with one or more additional warrants, debt securities, preferred stock, depositary shares or common stock, or any combination of those securities in the form of units, as described in the applicable prospectus supplement. If we issue warrants as part of a unit, the accompanying prospectus supplement will specify whether those warrants may be separated from the other securities in the unit prior to the warrants' expiration date. Below is a description of certain general terms and provisions of the warrants that we may offer. Further terms of the warrants will be described in the prospectus supplement.

        The applicable prospectus supplement will contain, where applicable, the following terms of and other information relating to the warrants:

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GLOBAL SECURITIES

General

        The debt securities and the capital securities may be issued in whole or in part in the form of one or more fully-registered global securities that will be deposited with, or on behalf of, a depository which, unless otherwise indicated in the applicable prospectus supplement for such securities, will be DTC. Global capital securities may be issued in either temporary or permanent form. Unless and until it is exchanged in whole or in part for securities in certificated form, a global security may not be transferred except as a whole in the following manner:

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        The specific terms of the depository arrangement with respect to any debt securities or capital securities will be described in the applicable prospectus supplement. We anticipate that the following provisions will apply to all depository arrangements.

        Upon the issuance of a global security and the deposit of such global security with or on behalf of the depository, the depository for such global security will credit, on its book-entry registration and transfer system, the respective principal amounts of the debt securities represented by such global security, or, in the case of capital securities, the respective aggregate liquidation amounts of the capital securities represented by such global security, to the accounts of persons that have accounts with such depository (each such person, a participant), which may include Euroclear and Clearstream. The accounts to be credited shall be designated by the dealers, underwriters or agents participating in the distribution of such debt securities or capital securities or by us if we have offered and sold such debt securities or capital securities directly. Ownership of beneficial interests in a global security will be limited to participants or persons that may hold interests through participants.

        Ownership of a beneficial interest in such global security will be shown on, and the transfer of that ownership will be effected only through, records maintained by the depository for such global security (with respect to interests of participants) or by participants or persons that hold through participants (with respect to interests of persons other than participants). The laws of some states require that certain purchasers of securities take physical delivery of such securities in certificated form. Such limits and such laws may impair the ability to own, transfer or pledge beneficial interests in a global security.

        So long as the depository for a global security, or its nominee, is the holder of such global security, such depository or such nominee, as the case may be, will be considered the sole owner or holder of the debt securities or capital securities represented by such global security for all purposes under the applicable indenture or trust agreement. Except as set forth below, owners of beneficial interests in a global security will not be entitled to have debt securities or capital securities represented by such global security registered in their names, will not receive or be entitled to receive physical delivery of securities in certificated form and will not be considered the owners or holders thereof under the applicable indenture or trust agreement. Accordingly, each person owning a beneficial interest in a global security must rely on the procedures of the depository for such global security and, if such person is not a participant, on the procedures of the participant through which such person owns its interest, to exercise any rights of a holder under the applicable indenture or trust agreement. We understand that under existing industry practices, if we request any action of holders or if an owner of a beneficial interest in a global security desires to give or take any action which a holder is entitled to give or take under the applicable indenture or trust agreement, the depository for such global security would authorize the participants holding the relevant beneficial interest to give or take such action, and such participants would authorize beneficial owners owning through such participants to give or take such action or would otherwise act upon the instructions of beneficial owners holding through them.

        Payments of principal of or premium, if any, and interest, if any, on debt securities or distributions or other payments on capital securities represented by a global security registered in the name of a depository or its nominee will be made to such depository or its nominee, as the case may be, as the registered owner or the holder of the global security representing such debt securities or capital securities. None of State Street, the trustee for such securities, any paying agent for such securities, the property trustee or the securities registrar, as applicable, will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global security for such securities or for maintaining, supervising or reviewing any records relating to such beneficial ownership interests.

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        We expect that the depository for any debt securities represented by a global debt security, upon receipt of any payment of principal, premium or interest, will credit immediately participants' accounts with payments in amounts proportionate to their respective beneficial interests in the principal amount of such global debt security as shown on the records of such depository. We also expect that the depository for a series of capital securities or its nominee, upon receipt of any payment of liquidation amount, redemption price, premium or distributions in respect of a permanent global capital security representing any of such capital securities, immediately will credit participants' accounts with payments in amounts proportionate to their respective beneficial interest in the aggregate liquidation amount of such global capital security for such capital securities as shown on the records of such depositary or its nominee. We further expect that payments by participants to owners of beneficial interests in any such global security held through such participants will be governed by standing instructions and customary practices, as is now the case with securities held for the accounts of customers in bearer form or registered in "street name," and will be the responsibility of such participants.

        Unless otherwise specified in the applicable prospectus supplement, no global debt security may be exchanged in whole or in part for debt securities registered, and no transfer of a global debt security in whole or in part may be registered, in the name of any person other than the depository for such global debt security or a nominee thereof unless:

        Unless otherwise specified in the applicable prospectus supplement, if a depository for a series of capital securities is at any time unwilling, unable or ineligible to continue as depository and a successor depository is not appointed by the trust within 90 days, the trust will issue individual capital securities of such series in exchange for the global capital security representing such series of capital securities. In addition, the trust may at any time and in its sole discretion, subject to any limitations described in the prospectus supplement relating to such capital securities, determine not to have any capital securities of such series represented by one or more global capital securities and, in such event, will issue individual capital securities of such series in exchange for the global capital security or securities representing such series of capital securities. Further, if the trust so specifies with respect to the capital securities of a series, an owner of a beneficial interest in a global capital security representing capital securities of such series may, on terms acceptable to the trust, the property trustee and the depository for such global capital security, receive individual capital securities of such series in exchange for such beneficial interests, subject to any limitations described in the prospectus supplement relating to such capital securities. In any such instance, an owner of a beneficial interest in a global capital security will be entitled to a physical delivery of individual capital securities of the series represented by such global capital security equal in liquidation amount to such beneficial interest and to have such capital securities registered in its name.

Book-Entry Issuance

        We expect DTC to act as securities depository for all of the debt securities. The debt securities will be issued only as fully-registered securities registered in the name of Cede & Co., DTC's nominee. DTC will thus be the only registered holder of the debt securities and will be considered the sole owner of the debt securities. One or more fully-registered global certificates will be issued for the debt securities, representing in the aggregate the aggregate principal balance of debt securities.

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        We also expect DTC to act as securities depository for all of the capital securities, unless otherwise specified in the prospectus supplement. The capital securities will be issued only as fully-registered securities registered in the name of Cede & Co. One or more fully-registered global certificates will be issued for the capital securities of each trust, representing in the aggregate the total number of such trust's capital securities, and will be deposited with the property trustee as custodian for DTC.

        In this prospectus and the accompanying prospectus supplement, for book-entry debt securities, references to actions taken by debt security holders will mean actions taken by DTC upon instructions from its participants, and reference to payments and notices of redemptions to debt security holders will mean payments and notices of redemption to DTC as the registered holder of the debt securities for distribution to the participants in accordance with DTC's procedures.

        DTC is a limited purpose trust company organized under the New York Banking Law, a "banking organization" within the meaning of the New York Banking Law, a member of the Federal Reserve System, a "clearing corporation" within the meaning of the New York Uniform Commercial Code, and a "clearing agency" registered pursuant to the provisions of Section 17A of the Exchange Act. DTC holds securities that its participants deposit with DTC. DTC also facilitates the settlement among participants of securities transactions, such as transfers and pledges, in deposited securities through electronic computerized book-entry changes in participants' accounts, thereby eliminating the need for physical movement of securities certificates. Direct participants include securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations. DTC is owned by a number of its direct participants and by the New York Stock Exchange, Inc., the American Stock Exchange, Inc. and the National Association of Securities Dealers, Inc. Access to the DTC system is also available to others such as securities brokers and dealers, banks and trust companies that clear through or maintain custodial relationships with direct participants, either directly or indirectly. The rules applicable to DTC and its participants are on file with the SEC.

        Purchases of debt securities or capital securities within the DTC system must be made by or through direct participants, which will receive a credit for the debt securities or capital securities on DTC's records. The ownership interest of each actual purchaser of each debt security or capital security (each a beneficial owner) is in turn to be recorded on the direct and indirect participants' records, including Euroclear and Clearstream. Beneficial owners will not receive written confirmation from DTC of their purchases, but beneficial owners are expected to receive written confirmations providing details of the transactions, as well as periodic statements of their holdings, from the direct or indirect participants through which the beneficial owners purchased their securities. Transfers of ownership interests in the securities are to be accomplished by entries made on the books of participants acting on behalf of beneficial owners. Beneficial owners will not receive certificates representing their ownership interests in their securities, except in limited circumstances.

        Transfers between participants will be effected in accordance with DTC's procedures and will be settled in same-day funds. Transfers between participants in Euroclear and Clearstream will be effected in the ordinary way in accordance with their respective rules and operating procedures.

        Cross-market transfers between participants, on the one hand, and Euroclear participants or Clearstream participants, on the other hand, will be effected by DTC in accordance with DTC's rules on behalf of Euroclear or Clearstream, as the case may be, by its respective depository; however, such cross-market transaction will require delivery of instructions to Euroclear or Clearstream, as the case may be, by the counterparty in such system in accordance with the rules and procedures and within the established deadlines of such system. Euroclear or Clearstream, as the case may be, will, if the transaction meets its settlement requirements, deliver instructions to its respective depository to take action to effect final settlement on its behalf by delivering or receiving interests in the debt securities or capital securities in DTC, and making or receiving payment in accordance with normal procedures.

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        Because of time zone differences, the securities account of a Euroclear or Clearstream participant purchasing an interest in a debt security or capital security from a participant in DTC will be credited, and any such crediting will be reported to the relevant Euroclear participant or Clearstream participant, during the securities settlement processing day (which must be a business day for Euroclear and Clearstream, as the case may be) immediately following the DTC settlement date. Cash received in Euroclear or Clearstream as a result of sales of interests in a debt security or capital security by or through a Euroclear or Clearstream participant to a participant in DTC will be received with value on the DTC settlement date but will be available in the relevant Euroclear or Clearstream cash account only as of the business day for Euroclear or Clearstream following the DTC settlement date.

        Links have been established among DTC, Clearstream Banking, société anonyme, and Euroclear Bank S.A./N.V. to facilitate the initial issuance of the debt securities and capital securities sold outside of the United States and cross-market transfers of the notes associated with secondary market trading.

        Although DTC, Clearstream and Euroclear have agreed to the procedures provided below in order to facilitate transfers, they are under no obligation to perform these procedures, and these procedures may be modified or discontinued at any time.

        Clearstream and Euroclear will record the ownership interests of their participants in much the same way as DTC, and DTC will record the total ownership of each of the U.S. agents of Clearstream and Euroclear, as participants in DTC. When debt securities or capital securities are to be transferred from the account of a DTC participant to the account of a Clearstream participant or a Euroclear participant, the purchaser must send instructions to Clearstream or Euroclear through a participant at least one day prior to settlement. Clearstream or Euroclear, as the case may be, will instruct its U.S. agent to receive debt securities or capital securities against payment. After settlement, Clearstream or Euroclear will credit its participant's account. Credit for the debt securities or capital securities will appear on the next day.

        Because settlement is taking place during New York business hours, DTC participants will be able to employ their usual procedures for sending debt securities or capital securities to the relevant U.S. agent acting for the benefit of Clearstream or Euroclear participants. The sale proceeds will be available to the DTC seller on the settlement date. As a result, to the DTC participant, a cross-market transaction will settle no differently than a trade between two DTC participants.

        When a Clearstream or Euroclear participant wishes to transfer debt securities or capital securities to a DTC participant, the seller will be required to send instructions to Clearstream or Euroclear through a participant at least one business day prior to settlement. In these cases, Clearstream or Euroclear will instruct its U.S. agent to transfer these notes against payment for them. The payment will then be reflected in the account of the Clearstream or Euroclear participant the following day, with the proceeds back-valued to the value date, which would be the preceding day, when settlement occurs in New York. If settlement is not completed on the intended value date, that is, the trade fails, proceeds credited to the Clearstream or Euroclear participant's account will instead be valued as of the actual settlement date.

        You should be aware that you will only be able to make and receive deliveries, payments and other communications involving the debt securities or capital securities through Clearstream and Euroclear on the days when those clearing systems are open for business. Those systems may not be open for business on days when banks, brokers and other institutions are open for business in the United States. In addition, because of time zone differences there may be problems with completing transactions involving Clearstream and Euroclear on the same business day as in the United States.

        Euroclear was created in 1968 to hold securities for participants of Euroclear and to clear and settle transactions between Euroclear participants through simultaneous electronic book-entry delivery against payment, thus eliminating the need for physical movement of certificates and risk from lack of

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simultaneous transfers of securities and cash. Transactions may now be settled through Euroclear in many currencies, including U.S. dollars and Japanese yen. Euroclear provides various other services, including securities lending and borrowing and interfaces with domestic markets in several countries generally similar to the arrangements for cross-market transfers with DTC.

        Euroclear is operated by the Euroclear Operator, under contract with Euroclear Clearance System plc, a U.K. corporation, or the "Euroclear Clearance System". The Euroclear Operator conducts all operations, and all Euroclear securities clearance accounts and Euroclear cash accounts are accounts with the Euroclear Operator, not Euroclear Clearance System. The Euroclear Clearance System establishes policy for Euroclear on behalf of Euroclear participants. Euroclear participants include banks (including central banks), securities brokers and dealers and other professional financial intermediaries and may include the underwriters of the debt securities offered by this prospectus or one or more of their affiliates. Indirect access to Euroclear is also available to other firms that clear through or maintain a custodial relationship with a Euroclear participant, either directly or indirectly. Euroclear is an indirect participant in DTC.

        The Euroclear Operator is a Belgian bank, which is regulated and examined by the Belgian Banking Commission and the National Bank of Belgium.

        The Terms and Conditions Governing Use of Euroclear and the related Operating Procedures of Euroclear and applicable Belgian law govern securities clearance accounts and cash accounts with the Euroclear Operator. Specifically, these terms and conditions govern transfers of securities and cash within Euroclear, withdrawal of securities and cash from Euroclear and receipts of payments with respect to securities in Euroclear.

        All securities in Euroclear are held on a fungible basis without attribution of specific certificates to specific securities clearance accounts. The Euroclear Operator acts under the terms and conditions only on behalf of Euroclear participants and has no record of or relationship with persons holding securities through Euroclear participants.

        Distributions with respect to debt securities held beneficially through Euroclear will be credited to the cash accounts of Euroclear participants in accordance with Euroclear's terms and conditions, to the extent received by the Euroclear Operator and by Euroclear.

        Clearstream was incorporated as a limited liability company under Luxembourg law. Clearstream is owned by Cedel International, société anonyme, and Deutsche Börse AG. The shareholders of these two entities are banks, securities dealers and financial institutions. Clearstream holds securities for its customers and facilitates the clearance and settlement of securities transactions between Clearstream customers through electronic book-entry changes in accounts of Clearstream customers, thus eliminating the need for physical movement of certificates. Clearstream provides to its customers, among other things, services for safekeeping, administration, clearance and settlement of internationally traded securities, securities lending and borrowing and collateral management. Clearstream interfaces with domestic markets in a number of countries. Clearstream has established an electronic bridge with the Euroclear Operator to facilitate settlement of trades between Clearstream and Euroclear.

        As a registered bank in Luxembourg, Clearstream is subject to regulation by the Luxembourg Commission for the Supervision of the Financial Sector. Clearstream participants are recognized financial institutions around the world, including underwriters, securities brokers and dealers, banks, trust companies and clearing corporations. In the United States, Clearstream participants are limited to securities brokers and dealers and banks, and may include the underwriters of the debt securities offered by means of this prospectus or one or more of their affiliates. Other institutions that maintain a custodial relationship with a Clearstream participant may obtain indirect access to Clearstream. Clearstream is an indirect participant in DTC.

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        Distributions with respect to the debt securities held beneficially through Clearstream will be credited to cash accounts of Clearstream participants in accordance with its rules and procedures, to the extent received by Clearstream.

        DTC has no knowledge of the actual beneficial owners of the debt securities or capital securities; DTC's records reflect only the identity of the direct participants to whose accounts such debt securities or capital securities are credited, which may or may not be the beneficial owners. The participants will remain responsible for keeping account of their holdings on behalf of their customers.

        Conveyance of notices and other communications by DTC to direct participants, by direct participants to indirect participants, and by direct participants and indirect participants to beneficial owners and the voting rights of direct participants, indirect participants and beneficial owners will be governed by arrangements among them, subject to any statutory or regulatory requirements as may be in effect from time to time.

        Redemption notices will be sent to Cede & Co. as the registered holder of the debt securities or capital securities. If less than all of the debt securities are being redeemed, or less than all of a trust's capital securities are being redeemed, DTC will determine the amount of the interest of each direct participant to be redeemed in accordance with its then current procedures.

        Although voting with respect to the debt securities and capital securities is limited to the holders of record of the debt securities and capital securities, respectively, in those instances in which a vote is required, neither DTC nor Cede & Co. will itself consent or vote with respect to the debt securities or capital securities, as applicable. Under its usual procedures, DTC would mail an omnibus proxy to the relevant trustee as soon as possible after the record date. Such omnibus proxy assigns Cede & Co.'s consenting or voting rights to those direct participants to whose accounts such debt securities or capital securities are credited on the record date (identified in a listing attached to the omnibus proxy).

        Distribution payments on the debt securities and capital securities will be made by the relevant trustee to DTC. DTC's usual practice is to credit direct participants' accounts on the relevant payment date in accordance with their respective holdings shown on DTC's records unless DTC has reason to believe that it will not receive payments on such payment date. Payments by participants to beneficial owners will be governed by standing instructions and customary practices and will be the responsibility of such participant and not of DTC, the relevant trustee, the trust thereof (in the case of capital securities) or State Street, subject to any statutory or regulatory requirements as may be in effect from time to time. Payment of distributions to DTC is the responsibility of the relevant trustee, and disbursements of such payments to the beneficial owners is the responsibility of direct and indirect participants.

        DTC may discontinue providing its services as securities depository with respect to any of the debt securities at any time by giving reasonable notice to the relevant trustee and to us. Under such circumstances, in the event that a successor securities depository is not obtained, definitive certificates representing such debt securities are required to be printed and delivered. Additionally, we, at our option, may decide to discontinue use of the system of book-entry transfers through DTC (or a successor depository). After an event of default, the holders of a majority in aggregate principal amount of debt securities may determine to discontinue the system of book-entry transfers through DTC. In any such event, definitive certificates for such debt securities will be printed and delivered.

        DTC may also discontinue providing its services as securities depository with respect to any of the capital securities at any time by giving reasonable notice to the relevant trustee and to us. In the event that a successor securities depository is not obtained, definitive capital security certificates representing such capital securities are required to be printed or delivered. Additionally, we, at our option, may decide to discontinue use of the system of book-entry transfers through DTC (or a successor depository). After an event of default, the holders of a majority in liquidation preference of capital

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securities may determine to discontinue the system of book-entry transfers through DTC. In any such event, definitive certificates for such capital securities will be printed and delivered.

        The information in this section concerning DTC and DTC's book-entry system, Euroclear and Clearstream has been obtained from sources that we and the trusts believe to be accurate, but we and the trusts assume no responsibility for the accuracy thereof. Neither we nor the trusts have any responsibility for the performance by DTC or its participants of their respective obligations as described herein or under the rules and procedures governing their respective operations.


PLAN OF DISTRIBUTION

        We and the trusts may sell securities:

        The distribution of the securities may be effected from time to time in one or more transactions:

        Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

        The prospectus supplement with respect to the securities of a particular series will describe the terms of the offering of the securities, including the following:

        Only the agents or underwriters named in the prospectus supplement are agents or underwriters in connection with the securities being offered.

        We may agree to enter into an agreement to indemnify the agents and the several underwriters against certain civil liabilities, including liabilities under the Securities Act or to contribute to payments the agents or the underwriters may be required to make.

        If so indicated in the applicable prospectus supplement, we will authorize underwriters or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in the prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in the prospectus supplement. Institutions with whom the contracts, when authorized, may be made

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include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

        Certain of the underwriters and their associates and affiliates may be customers of, have borrowing relationships with, engage in other transactions with, and/or perform services, including investment banking services, for, us or one or more of our affiliates in the ordinary course of business.

        Certain of the underwriters may use this prospectus and the accompanying prospectus supplement for offers and sales related to market-making transactions in the securities. These underwriters may act as principal or agent in these transactions, and the sales will be made at prices related to prevailing market prices at the time of sale.

        The securities may be new issues of securities and may have no established trading market. The securities may or may not be listed on a national securities exchange or the Nasdaq National Market. We can make no assurance as to the liquidity of or the existence of trading markets for any of the securities.


VALIDITY OF SECURITIES

        Unless the applicable prospectus supplement indicates otherwise, certain matters of Delaware law relating to the validity of the capital securities, the enforceability of the applicable trust agreement and the creation of each trust will be passed upon for State Street and for the trusts by Richards, Layton & Finger, P.A., special Delaware counsel to State Street and the trusts. Unless the applicable prospectus supplement indicates otherwise, certain legal matters will be passed upon by Ropes & Gray LLP for State Street and the trusts. Truman S. Casner, a partner of Ropes & Gray LLP, is a director of State Street. Mr. Casner owns beneficially a total of 53,347 shares of common stock of State Street. Ropes & Gray LLP performs services for State Street from time to time. Ropes & Gray LLP will rely on Richards, Layton & Finger, P.A. as to all matters of Delaware law.


EXPERTS

        The consolidated financial statements of State Street Corporation appearing in State Street Corporation's Annual Report (Form 10-K) for the year ended December 31, 2005, and State Street Corporation management's assessment of the effectiveness of internal control over financial reporting as of December 31, 2005 included therein, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements and management's assessment are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

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              Shares

GRAPHIC

State Street Corporation

Common Stock

PROSPECTUS SUPPLEMENT

Goldman, Sachs & Co.
Morgan Stanley
Credit Suisse
Lehman Brothers
UBS Investment Bank

                        , 2008