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 *
Kohn Leslie
  2. Issuer Name and Ticker or Trading Symbol
AMBARELLA INC [AMBA]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Technology Officer
(Last)
(First)
(Middle)
3101 JAY STREET
3. Date of Earliest Transaction (Month/Day/Year)
12/18/2018
(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 12/18/2018   M   6,650 A (1) 916,646 D  
Ordinary Shares 12/18/2018   S(2)   4,990 D $ 38 911,656 D  

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
Restricted Stock Units (1) 12/18/2018   M     2,613   (3) 09/15/2019(3) Ordinary Shares 2,613 $ 0 7,840 D  
Restricted Stock Units (1) 12/18/2018   M     4,037   (4) 06/15/2021(4) Ordinary Shares 4,037 $ 0 40,370 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Kohn Leslie
3101 JAY STREET
SANTA CLARA, CA 95054
  X     Chief Technology Officer  

Signatures

 By: /s/ Michael Morehead, Attorney in Fact For: Leslie Kohn   12/20/2018
**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) Shares sold to pay tax obligations resulting from the vesting of restricted stock awards and restricted stock units.
(3) The RSUs vest as to 1/10 of the RSUs on June 15, 2017 and 1/10 of the RSUs will vest each three months thereafter such that the RSUs are 100% vested on September 15, 2019.
(4) The restricted stock units vest at the rate of 1/12 per quarter commencing on June 15, 2018.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

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