Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Blackstone Management Associates VI L.L.C.
  2. Issuer Name and Ticker or Trading Symbol
KNIGHT CAPITAL GROUP, INC. [KCG]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O THE BLACKSTONE GROUP L.P., 345 PARK AVENUE
3. Date of Earliest Transaction (Month/Day/Year)
02/28/2013
(Street)

NEW YORK, NY 10154
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Class A Common Stock 02/28/2013   C(1)   56,502,694 A (2) 56,502,694 I See Footnotes (3) (6) (7) (10) (11)
Class A Common Stock 02/28/2013   C(1)   28,666 A (2) 28,666 I See Footnotes (4) (6) (7) (10) (11)
Class A Common Stock 02/28/2013   C(1)   344,000 A (2) 344,000 I See Footnotes (5) (6) (7) (10) (11)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Series A-1 Cumulative Perpetual Convertible Preferred Stock (2) 02/28/2013   C(1)     84,754   (2)   (2) Class A Common Stock 56,502,694 (2) 0 I See Footnotes (3) (6) (7) (10) (11)
Series A-1 Cumulative Perpetual Convertible Preferred Stock (2) 02/28/2013   C(1)     43   (2)   (2) Class A Common Stock 28,666 (2) 0 I See Footnotes (4) (6) (7) (10) (11)
Series A-1 Cumulative Perpetual Convertible Preferred Stock (2) 02/28/2013   C(1)     516   (2)   (2) Class A Common Stock 344,000 (2) 0 I See Footnotes (5) (6) (7) (10) (11)
Restricted Stock Units (8)               (8)   (8) Class A Common Stock 35,461   35,461 I See Footnotes (8) (9) (10) (11)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Blackstone Management Associates VI L.L.C.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE
NEW YORK, NY 10154
    X    
Blackstone Capital Partners VI L.P.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    
Blackstone Family Investment Partnership VI L.P.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    
Blackstone Family Investment Partnership VI ESC L.P.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    
BMA VI L.L.C.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    
BCP VI Side-By-Side GP L.L.C.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    

Signatures

 BLACKSTONE CAPITAL PARTNERS VI L.P., By: Blackstone Management Associates VI, L.L.C., its general partner, By: BMA VI, L.L.C., its sole member, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   05/28/2013
**Signature of Reporting Person Date

 BLACKSTONE FAMILY INVESTMENT PARTNERSHIP VI L.P., By: BCP VI Side-by-Side GP, L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   05/28/2013
**Signature of Reporting Person Date

 BLACKSTONE FAMILY INVESTMENT PARTNERSHIP VI ESC L.P., By: BCP VI Side-by-Side GP, L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   05/28/2013
**Signature of Reporting Person Date

 BLACKSTONE MANAGEMENT ASSOCIATES VI L.L.C., By: BMA VI, L.L.C., its sole member, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   05/28/2013
**Signature of Reporting Person Date

 BMA VI L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   05/28/2013
**Signature of Reporting Person Date

 BCP VI SIDE-BY-SIDE GP L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer   05/28/2013
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Mandatory conversion for no additional consideration, pursuant to the Certificate of Designations (the "Certificate of Designations") applicable to the Series A-1 Cumulative Perpetual Convertible Preferred Stock, par value $0.01 per share (the "Series A-1 Preferred Stock") of the Series A-1 Preferred Stock into the Issuer's Class A Common Stock, par value $0.01 per share (the "Common Stock").
(2) Shares of Series A-1 Preferred Stock were convertible in accordance with the terms thereof at an initial conversion rate of 666.667 shares of Common Stock per $1,000 of stated value of Series A-1 Preferred Stock (subject to certain adjustments). In addition, if the closing price of the Common Stock exceeded 200% of the then applicable conversion price for 60 consecutive trading days, all of the outstanding shares of Series A-1 Preferred Stock would mandatorily convert into shares of Common Stock at a ratio of 666.667 shares of Common Stock for each share of Series A-1 Preferred Stock (subject to certain adjustments), which reflects an approximate initial conversion price of $1.50 per share of Common Stock. All Series A-1 Preferred Stock mandatorily converted on February 28, 2013.
(3) Represents securities directly held by Blackstone Capital Partners VI L.P.
(4) Represents securities directly held by Blackstone Family Investment Partnership VI L.P.
(5) Represents securities directly held by Blackstone Family Investment Partnership VI ESC L.P. (collectively, with Blackstone Capital Partners VI L.P. and Blackstone Family Investment Partnership VI L.P., the "Blackstone Funds").
(6) Blackstone Management Associates VI L.L.C. is the general partner of Blackstone Capital Partners VI L.P. BMA VI L.L.C. is the sole member of Blackstone Management Associates VI L.L.C. BCP VI Side-By-Side GP L.L.C. is the general partner of Blackstone Family Investment Partnership VI L.P. and Blackstone Family Investment Partnership VI ESC L.P.
(7) Blackstone Holdings III L.P. is the managing member and the owner of a majority in interest of BMA VI L.L.C. and the sole member of BCP VI Side-By-Side GP L.L.C. Blackstone Holdings III GP L.P. is the general partner of Blackstone Holdings III L.P. The general partner of Blackstone Holdings III GP L.P. is Blackstone Holdings III GP Management L.L.C. The sole member of Blackstone Holdings III GP Management L.L.C. is The Blackstone Group L.P. The general partner of The Blackstone Group L.P. is Blackstone Group Management L.L.C. Blackstone Group Management L.L.C. is wholly owned by Blackstone's senior managing directors and controlled by its founder, Stephen A. Schwarzman.
(8) Restricted stock units granted to Blackstone Management Partners L.L.C. pursuant to the Knight Capital Group, Inc. 2010 Equity Incentive Plan in connection with Martin Brand's service on the board of directors of the Issuer. The restricted stock units vest on August 27, 2016 or upon earlier retirement by Mr. Brand and will be settled upon vesting. Each restricted stock unit represents a contingent right to receive one share of Common Stock.
(9) The Blackstone Group, L.P., Blackstone Group Management L.L.C. and Mr. Schwarzman may be deemed to indirectly control Blackstone Management Partners L.L.C.
(10) Due to the limitations of the electronic filing system, Blackstone Holdings III L.P., Blackstone Holdings III GP L.P., Blackstone Holdings III GP Management L.L.C., The Blackstone Group L.P., Blackstone Group Management L.L.C. and Stephen A. Schwarzman are filing a separate Form 4.
(11) Each of the Reporting Persons, other than the Blackstone Funds to the extent of their direct holdings, disclaims beneficial ownership of such Common Stock, except to the extent of such Reporting Person's pecuniary interest therein, and, pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, each of the Reporting Persons, including the Blackstone Funds, states that the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.

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