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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1. Name and Address of Reporting Person * BENCHMARK CAPITAL MANAGEMENT CO IV LLC   2. Issuer Name and Ticker or Trading Symbol AMBARELLA INC [AMBA] 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) 2480 SAND HILL ROAD, SUITE 200 3. Date of Earliest Transaction (Month/Day/Year) 10/15/2012 (Street) MENLO PARK, CA 94025 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 Ordinary Shares 10/15/2012   C   2,777,777 A (2) 2,777,777 I See footnote (1) Ordinary Shares 10/15/2012   C   558,347 A (3) 3,336,124 I See footnote (1) Ordinary Shares 10/15/2012   C   370,370 A (4) 3,706,494 I See footnote (1) Ordinary Shares 10/15/2012   S   555,974 D $ 6 3,150,520 I See footnote (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 Convertible Preference Shares

(2)

10/15/2012

C

2,777,777

(2)

(2)

Ordinary Shares

2,777,777

$ 0

0

I

See footnotes (1)

Series B Convertible Preference Shares

(3)

10/15/2012

C

558,347

(3)

(3)

Ordinary Shares

558,347

$ 0

0

I

See footnotes (1)

Series C Convertible Preference Shares

(4)

10/15/2012

C

370,370

(4)

(4)

Ordinary Shares

370,370

$ 0

0

I

See footnotes (1)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
BENCHMARK CAPITAL MANAGEMENT CO IV LLC 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
BENCHMARK CAPITAL PARTNERS IV LP 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
BENCHMARK FOUNDERS FUND IV LP 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
BENCHMARK FOUNDERS FUND IV A LP 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
BENCHMARK FOUNDERS FUND IV-B LP 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
HARVEY KEVIN 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
BALKANSKI ALEXANDRE 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
SPURLOCK STEVEN M 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
GURLEY J WILLIAM 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X
KAGLE ROBERT 2480 SAND HILL ROAD SUITE 200 MENLO PARK, CA 94025		X

Signatures

/s/ Steven M. Spurlock, as Managing Member of Benchmark Capital Management Co. IV, L.L.C.		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock, as Managing Member of Benchmark Capital Management Co. IV, L.L.C., the General Partner of Benchmark Capital Partners IV, L.P.		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock, as Managing Member of Benchmark Capital Management Co. IV, L.L.C., the General Partner of Benchmark Founders' Fund IV, L.P.		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock, as Managing Member of Benchmark Capital Management Co. IV, L.L.C., the General Partner of Benchmark Founders' Fund IV-A, L.P.		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock, as Managing Member of Benchmark Capital Management Co. IV, L.L.C., the General Partner of Benchmark Founders' Fund IV-B, L.P.		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock, by power of attorney for Kevin R. Harvey		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock, by power of attorney for Alexandre Balkanski		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock, by power of attorney for J. William Gurley		10/15/2012
**Signature of Reporting Person		Date
/s/ Steven M. Spurlock, by power of attorney for Robert C. Kagle		10/15/2012
**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)	Shares held of record by Benchmark Capital Partners IV, L.P. or BCP IV, as nominee for Benchmark Capital Partners IV, L.P., Benchmark Founders' Fund IV, L.P., Benchmark Founders' Fund IV-A, L.P., and Benchmark Founders' Fund IV-B, L.P. and related individuals, or the Benchmark Funds. Benchmark Capital Management Co IV, L.L.C., or BCMC IV, is the general partner of BCP IV. BCMC IV's managing members are Alexandre Balkanski, Bruce W. Dunlevie, J. William Gurley, Kevin R. Harvey, Robert C. Kagle and Steven M. Spurlock. These individuals may be deemed to have shared voting and investment power over the shares held by the Benchmark Funds. Each of these indivduals disclaims beneficial ownership of such shares except to the extent of such individual's pecuniary interest therein.
(2)	The Series A Convertible Preference Shares converted into Ordinary Shares on a 1-to-1 basis and had no expiration date.
(3)	The Series A Convertible Preference Shares converted into Ordinary Shares on a 1-to-1 basis and had no expiration date.
(4)	The Series A Convertible Preference Shares converted into Ordinary Shares on a 1-to-1 basis and had no expiration date.
Remarks: Alexandre Balkanski, Bruce W. Dunlevie, J. William Gurley, Kevin R. Harvey, Robert C. Kagle and Steven M. Spurlock are the managing members of Benchmark Capital Management Co IV, L.L.C., which serves as general partner to Benchmark Capital Partners IV, L.P., Benchmark Founders' Fund IV, Benchmark Founders Fund IV-A, L.P. and Benchmark Founders Fund IV-B, L.P. and may be deemed to share voting and investment power over the shares beneficially held by such entities.  Each such person and entity disclaims the existence of a "group" and disclaims beneficial ownership of any securities (except to the extent of such person's or entity's pencuniary interest in such securities ) other than any securities being reported herein as being directly owned by such person or entity. The filing of this report is not an admission that any Reporting Persons is the beneficial owners of these shares for purposes of Section 16 or for any other purpose.  *This report is one of two reports, each on a separate Form 4, but relating to the same transaction being filed by entities affiliated with Benchmark Capital and their applicable members.

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