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)
10/13/2016

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	10/13/2016		S		346,202(1)	D	$96.5(2)	2,550,127(3)	I	See Footnotes(4)(5)

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 shares sold by the following entities: 262,832 shares sold by Summit Partners Venture Capital Fund III-A, L.P., 79,661 shares sold by Summit Partners Venture Capital Fund III-B, L.P., 3,424 shares sold by Summit Investors I, LLC and 285 shares sold by Summit Investors I (UK), L.P.

2. Represents the offering price to the public of $100 per share, net of underwriters' discount of $3.50.

3. Consists of 1,936,021 shares held by Summit Partners Venture Capital Fund III-A, L.P., 586,781 shares held by Summit Partners Venture Capital Fund III-B, L.P., 25,224 shares held by Summit Investors I, LLC and 2,101 shares held by Summit Investors I (UK), L.P.

4. 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 voting and dispositive power, to Summit Partners, L.P. and its investment committee responsible for voting and investment decisions with respect to the Issuer.

5. Summit Partners, L.P., through a three-person investment committee responsible for voting and investment decisions with respect to the Issuer, currently comprised of Martin J. Mannion, Bruce R. Evans and Peter Y. Chung, has voting and dispositive power over the shares held by each of these entities and therefore may be deemed to beneficially own such shares. Mr. Chung is a member of Summit Master Company, LLC. Mr. Chung may be deemed to share beneficial ownership of the shares of the Issuer held of record by the Summit entities and has an indirect pecuniary interest in such shares through his membership in Summit Master Company, LLC. Mr. Chung expressly disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein.

	/s/ Robin W. Devereux, Power of Attorney for Peter Y. Chung	10/14/2016
	** Signature of Reporting Person	Date
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