Chung Peter Y Form 4 Acacia Communications / PETER Y CHUNG ownership change

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

CHUNG PETER Y

(Last) (First) (Middle)

C/O SUMMIT PARTNERS

222 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Acacia Communications, Inc. [ ACIA ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
05/18/2017

4. If Amendment, Date of 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

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
Common Stock	05/18/2017		A		4,446(1)	A	$0	1,304,573(2)	I	See Remarks.(3)(4)

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 Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Represents restricted stock units awarded to Mr. Chung as compensation for services rendered as a director . Each restricted stock unit represents the right to receive one share of common stock upon vesting. The restricted stock units will vest entirely on May 18, 2018. Mr. Chung holds any restricted stock units for the benefit of Summit Partners, L.P., which he has empowered to determine when the underlying shares will be sold and which is entitled to the proceeds of any such sales.

2. Consists of 987,039 shares held by Summit Partners Venture Capital Fund III-A, L.P., 299,157 shares held by Summit Partners Venture Capital Fund III-B, L.P., 12,860 shares held by Summit Investors I, LLC; 1,071 shares held by Summit Investors I (UK), L.P.and 4,446 restricted stock units held in the name of Peter Y. Chung, which are held for the benefit of Summit Partners, L.P.

3. Summit Partners, L.P. is the managing member of Summit Partners VC III, LLC, which is the general partner of Summit Partners VC III, L.P., which is the general partner of each of Summit Partners Venture Capital Fund III-A, L.P. and Summit Partners Venture Capital Fund III-B, L.P. Summit Master Company, LLC is the managing member of Summit Investors Management, LLC, which is the manager of Summit Investors I, LLC, and the general partner of Summit Investors I (UK), L.P. Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated investment decisions, including dispositive power, to Summit Partners, L.P. and its investment committee responsible for voting and investment decisions with respect to the Issuer.

4. Summit Partners, L.P., through a two-person investment committee responsible for voting and investment decisions with respect to the Issuer, currently comprised of Martin J. Mannion and Peter Y. Chung, has voting and dispositive power over the shares held by each of the entities listed above and Mr. Chung and therefore, may be deemed to beneficially own such shares. Mr. Chung is a member of Summit Master Company, LLC. Each of Summit Partners, L.P., the entities listed above, Mr. Mannion and Mr. Chung expressly disclaims beneficial ownership of such shares except to the extent of their pecuniary interest therein.

	Robin W. Devereux, Power of Attorney for Peter Y. Chung	05/22/2017
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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