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 * Day Christopher   2. Issuer Name and Ticker or Trading Symbol AMBARELLA INC [AMBA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) VP of Marketing (Last) (First) (Middle) 3101 JAY STREET 3. Date of Earliest Transaction (Month/Day/Year) 09/16/2014 (Street) SANTA CLARA, CA 95054 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ 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 09/16/2014   M   1,494 A (1) 36,876 (2) D   Ordinary Shares 09/16/2014   S(3)   1,385 D $ 33.66 35,491 D

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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

Restricted Stock Units

(1)

09/16/2014

M

556

(4)

08/27/2022(4)

Ordinary Shares

556

$ 0

4,445

D

Restricted Stock Units

(1)

09/16/2014

M

938

(5)

08/26/2023(6)

Ordinary Shares

938

$ 0

5,625

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Day Christopher 3101 JAY STREET SANTA CLARA, CA 95054			VP of Marketing

Signatures

By: /s/ Michael Morehead, Attorney in Fact For: Christopher Day		09/17/2014
**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)	Each restricted stock unit represents a contingent right to receive one share of Ambarella, Inc. Ordinary Shares.
(2)	Includes 375 shares acquired under the Company's employee stock purchase plan on September 15, 2014.
(3)	Shares sold to pay tax obligations resulting from the vesting of restricted stock units.
(4)	The restricted stock units vest at the rate of 1/16 per quarter beginning on September 15, 2012.
(5)	On August 27, 2013 the reporting person was granted RSUs convertible into 7,500 Ordinary Shares based on Issuer's determination of the satisfaction of certain performance goals for the fiscal year ended January 31, 2014. The performance criteria were achieved, and the RSUs become eligible for time-based vesting commencing on March 15, 2014.
(6)	The RSUs vested as to 1/8 of the RSUs on June 15, 2014 and 1/8 of the RSU's will vest each three months thereafter such that the RSUs are 100% vested on March 15, 2016.

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