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 *
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, Marketing
(Last)
(First)
(Middle)
3101 JAY STREET
3. Date of Earliest Transaction (Month/Day/Year)
03/07/2019
(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 03/08/2019   S   4,442 D $ 40.536 (1) 12,827 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
Performance Stock Units (2) 03/07/2019   A   8,011     (3) 03/15/2022(3) Ordinary Shares 8,011 $ 0 8,011 D  
Restricted Stock Units (2) 03/07/2019   A   8,011     (4) 03/15/2022(4) Ordinary Shares 8,011 $ 0 8,011 D  

Reporting Owners

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

Signatures

 By: /s/ Michael Morehead, Attorney in Fact For: Christopher Day   03/11/2019
**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) The sale price reported in column 4 of Table I represents the weighted average sale price of the shares sold ranging from $40.4530 to $40.5486 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the reporting person will provide full information regarding the number of shares sold at each separate price within the ranges set forth in this Form 4.
(2) Each restricted stock unit represents a contingent right to receive one share of Ambarella, Inc. Ordinary Shares.
(3) Reporting person was granted an award of performance-based RSUs covering a target of 8,011 ordinary shares (the "Target RSU Number"). Pursuant to time-based vesting requirements, 100% of this award is scheduled to vest on March 15, 2022, subject to continued service requirements through such date. In addition, the number of shares subject to the RSUs may be increased or decreased by up to 100% of the Target RSU Number or may remain the same, based on attainment of specified levels of the Company's total stockholder return over the period of February 1, 2019 through January 31, 2022.
(4) The restricted stock units vest at the rate of 1/12 per quarter commencing on March 15, 2019.

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