SC 13D/A 1 sc13da206297316_06152023.htm AMENDMENT NO. 2 TO THE SCHEDULE 13D

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO

§ 240.13d-2(a)

(Amendment No. 2)¹

Mercury Systems, Inc.

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

589378108

(CUSIP Number)

JEFFREY C. SMITH

STARBOARD VALUE LP

777 Third Avenue, 18th Floor

New York, New York 10017

(212) 845-7977

ANDREW FREEDMAN, ESQ.

MEAGAN REDA, ESQ.

OLSHAN FROME WOLOSKY LLP

1325 Avenue of the Americas

New York, New York 10019

(212) 451-2300

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

June 13, 2023

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box ¨.

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7 for other parties to whom copies are to be sent.

1 The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 589378108


	1	NAME OF REPORTING PERSON

			STARBOARD VALUE LP
	2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP				(a) ☐
						(b) ☐

	3	SEC USE ONLY


	4	SOURCE OF FUNDS

			OO
	5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)				☐


	6	CITIZENSHIP OR PLACE OF ORGANIZATION

			DELAWARE
NUMBER OF			7	SOLE VOTING POWER
SHARES
BENEFICIALLY					2,660,258
OWNED BY			8	SHARED VOTING POWER
EACH
REPORTING					- 0 -
PERSON WITH			9	SOLE DISPOSITIVE POWER

					2,660,258
			10	SHARED DISPOSITIVE POWER

					- 0 -
	11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

			2,660,258
	12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES				☐


	13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

			4.6%
	14	TYPE OF REPORTING PERSON

			PN

CUSIP No. 589378108


	1	NAME OF REPORTING PERSON

			STARBOARD VALUE AND OPPORTUNITY MASTER FUND LTD
	2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP				(a) ☐
						(b) ☐

	3	SEC USE ONLY


	4	SOURCE OF FUNDS

			WC
	5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)				☐


	6	CITIZENSHIP OR PLACE OF ORGANIZATION

			CAYMAN ISLANDS
NUMBER OF			7	SOLE VOTING POWER
SHARES
BENEFICIALLY					1,518,803
OWNED BY			8	SHARED VOTING POWER
EACH
REPORTING					- 0 -
PERSON WITH			9	SOLE DISPOSITIVE POWER

					1,518,803
			10	SHARED DISPOSITIVE POWER

					- 0 -
	11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

			1,518,803
	12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES				☐


	13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

			2.6%
	14	TYPE OF REPORTING PERSON

			CO

CUSIP No. 589378108

NAME OF REPORTING PERSON

STARBOARD VALUE AND OPPORTUNITY S LLC

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ☐

(b) ☐

SEC USE ONLY

SOURCE OF FUNDS

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)

☐

CITIZENSHIP OR PLACE OF ORGANIZATION

DELAWARE

NUMBER OF

SOLE VOTING POWER

BENEFICIALLY

194,038

OWNED BY

SHARED VOTING POWER

EACH

REPORTING

- 0 -

PERSON WITH

SOLE DISPOSITIVE POWER

194,038

SHARED DISPOSITIVE POWER

- 0 -

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

194,038

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

Less than 1%

TYPE OF REPORTING PERSON

CUSIP No. 589378108

NAME OF REPORTING PERSON

STARBOARD VALUE AND OPPORTUNITY C LP

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ☐

(b) ☐

SEC USE ONLY

SOURCE OF FUNDS

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)

☐

CITIZENSHIP OR PLACE OF ORGANIZATION

DELAWARE

NUMBER OF

SOLE VOTING POWER

BENEFICIALLY

144,322

OWNED BY

SHARED VOTING POWER

EACH

REPORTING

- 0 -

PERSON WITH

SOLE DISPOSITIVE POWER

144,322

SHARED DISPOSITIVE POWER

- 0 -

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

144,322

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

Less than 1%

TYPE OF REPORTING PERSON

CUSIP No. 589378108

NAME OF REPORTING PERSON

STARBOARD VALUE R LP

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ☐

(b) ☐

SEC USE ONLY

SOURCE OF FUNDS

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)

☐

CITIZENSHIP OR PLACE OF ORGANIZATION

DELAWARE

NUMBER OF

SOLE VOTING POWER

BENEFICIALLY

144,322

OWNED BY

SHARED VOTING POWER

EACH

REPORTING

- 0 -

PERSON WITH

SOLE DISPOSITIVE POWER

144,322

SHARED DISPOSITIVE POWER

- 0 -

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

144,322

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

Less than 1%

TYPE OF REPORTING PERSON

CUSIP No. 589378108

NAME OF REPORTING PERSON

STARBOARD VALUE AND OPPORTUNITY MASTER FUND L LP

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ☐

(b) ☐

SEC USE ONLY

SOURCE OF FUNDS

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)

☐

CITIZENSHIP OR PLACE OF ORGANIZATION

CAYMAN ISLANDS

NUMBER OF

SOLE VOTING POWER

BENEFICIALLY

100,784

OWNED BY

SHARED VOTING POWER

EACH

REPORTING

- 0 -

PERSON WITH

SOLE DISPOSITIVE POWER

100,784

SHARED DISPOSITIVE POWER

- 0 -

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

100,784

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

Less than 1%

TYPE OF REPORTING PERSON

CUSIP No. 589378108

NAME OF REPORTING PERSON

STARBOARD VALUE L LP

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ☐

(b) ☐

SEC USE ONLY

SOURCE OF FUNDS

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)

☐

CITIZENSHIP OR PLACE OF ORGANIZATION

DELAWARE

NUMBER OF

SOLE VOTING POWER

BENEFICIALLY

100,784

OWNED BY

SHARED VOTING POWER

EACH

REPORTING

- 0 -

PERSON WITH

SOLE DISPOSITIVE POWER

100,784

SHARED DISPOSITIVE POWER

- 0 -

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

100,784

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

Less than 1%

TYPE OF REPORTING PERSON

CUSIP No. 589378108

NAME OF REPORTING PERSON

STARBOARD VALUE R GP LLC

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ☐

(b) ☐

SEC USE ONLY

SOURCE OF FUNDS

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)

☐

CITIZENSHIP OR PLACE OF ORGANIZATION

DELAWARE

NUMBER OF

SOLE VOTING POWER

BENEFICIALLY

245,106

OWNED BY

SHARED VOTING POWER

EACH

REPORTING

- 0 -

PERSON WITH

SOLE DISPOSITIVE POWER

245,106

SHARED DISPOSITIVE POWER

- 0 -

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

245,106

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

Less than 1%

TYPE OF REPORTING PERSON

CUSIP No. 589378108

NAME OF REPORTING PERSON

STARBOARD X MASTER FUND LTD

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) ☐

(b) ☐

SEC USE ONLY

SOURCE OF FUNDS

CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)

☐

CITIZENSHIP OR PLACE OF ORGANIZATION

CAYMAN ISLANDS

NUMBER OF

SOLE VOTING POWER

BENEFICIALLY

381,415

OWNED BY

SHARED VOTING POWER

EACH

REPORTING

- 0 -

PERSON WITH

SOLE DISPOSITIVE POWER

381,415

SHARED DISPOSITIVE POWER

- 0 -

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

381,415

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES

☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

Less than 1%

TYPE OF REPORTING PERSON

CUSIP No. 589378108


	1	NAME OF REPORTING PERSON

			STARBOARD VALUE GP LLC
	2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP				(a) ☐
						(b) ☐

	3	SEC USE ONLY


	4	SOURCE OF FUNDS

			OO
	5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)				☐


	6	CITIZENSHIP OR PLACE OF ORGANIZATION

			DELAWARE
NUMBER OF			7	SOLE VOTING POWER
SHARES
BENEFICIALLY					2,660,258
OWNED BY			8	SHARED VOTING POWER
EACH
REPORTING					- 0 -
PERSON WITH			9	SOLE DISPOSITIVE POWER

					2,660,258
			10	SHARED DISPOSITIVE POWER

					- 0 -
	11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

			2,660,258
	12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES				☐


	13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

			4.6%
	14	TYPE OF REPORTING PERSON

			OO

CUSIP No. 589378108


	1	NAME OF REPORTING PERSON

			STARBOARD PRINCIPAL CO LP
	2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP				(a) ☐
						(b) ☐

	3	SEC USE ONLY


	4	SOURCE OF FUNDS

			OO
	5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)				☐


	6	CITIZENSHIP OR PLACE OF ORGANIZATION

			DELAWARE
NUMBER OF			7	SOLE VOTING POWER
SHARES
BENEFICIALLY					2,660,258
OWNED BY			8	SHARED VOTING POWER
EACH
REPORTING					- 0 -
PERSON WITH			9	SOLE DISPOSITIVE POWER

					2,660,258
			10	SHARED DISPOSITIVE POWER

					- 0 -
	11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

			2,660,258
	12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES				☐


	13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

			4.6%
	14	TYPE OF REPORTING PERSON

			PN

CUSIP No. 589378108


	1	NAME OF REPORTING PERSON

			STARBOARD PRINCIPAL CO GP LLC
	2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP				(a) ☐
						(b) ☐

	3	SEC USE ONLY


	4	SOURCE OF FUNDS

			OO
	5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)				☐


	6	CITIZENSHIP OR PLACE OF ORGANIZATION

			DELAWARE
NUMBER OF			7	SOLE VOTING POWER
SHARES
BENEFICIALLY					2,660,258
OWNED BY			8	SHARED VOTING POWER
EACH
REPORTING					- 0 -
PERSON WITH			9	SOLE DISPOSITIVE POWER

					2,660,258
			10	SHARED DISPOSITIVE POWER

					- 0 -
	11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

			2,660,258
	12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES				☐


	13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

			4.6%
	14	TYPE OF REPORTING PERSON

			OO

CUSIP No. 589378108


	1	NAME OF REPORTING PERSON

			JEFFREY C. SMITH
	2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP				(a) ☐
						(b) ☐

	3	SEC USE ONLY


	4	SOURCE OF FUNDS

			OO
	5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)				☐


	6	CITIZENSHIP OR PLACE OF ORGANIZATION

			USA
NUMBER OF			7	SOLE VOTING POWER
SHARES
BENEFICIALLY					- 0 -
OWNED BY			8	SHARED VOTING POWER
EACH
REPORTING					2,660,258
PERSON WITH			9	SOLE DISPOSITIVE POWER

					- 0 -
			10	SHARED DISPOSITIVE POWER

					2,660,258
	11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

			2,660,258
	12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES				☐


	13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

			4.6%
	14	TYPE OF REPORTING PERSON

			IN

CUSIP No. 589378108


	1	NAME OF REPORTING PERSON

			PETER A. FELD
	2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP				(a) ☐
						(b) ☐

	3	SEC USE ONLY


	4	SOURCE OF FUNDS

			OO
	5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEM 2(d) OR 2(e)				☐


	6	CITIZENSHIP OR PLACE OF ORGANIZATION

			USA
NUMBER OF			7	SOLE VOTING POWER
SHARES
BENEFICIALLY					- 0 -
OWNED BY			8	SHARED VOTING POWER
EACH
REPORTING					2,660,258
PERSON WITH			9	SOLE DISPOSITIVE POWER

					- 0 -
			10	SHARED DISPOSITIVE POWER

					2,660,258
	11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

			2,660,258
	12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES				☐


	13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

			4.6%
	14	TYPE OF REPORTING PERSON

			IN

CUSIP No. 589378108

The following constitutes Amendment No. 2 to the Schedule 13D filed by the undersigned (“Amendment No. 2”). This Amendment No. 2 amends the Schedule 13D as specifically set forth herein.

Item 3.

Source and Amount of Funds or Other Consideration.

Item 3 is hereby amended and restated to read as follows:

The Shares purchased by each of Starboard V&O Fund, Starboard S LLC, Starboard C LP, Starboard L Master, Starboard X Master and held in the Starboard Value LP Account were purchased with working capital (which may, at any given time, include margin loans made by brokerage firms in the ordinary course of business) in open market purchases, except as otherwise noted, as set forth in Schedule A, which is incorporated by reference herein.

The aggregate purchase price of the 1,518,803 Shares beneficially owned by Starboard V&O Fund is approximately $77,471,862, excluding brokerage commissions. The aggregate purchase price of the 194,038 Shares beneficially owned by Starboard S LLC is approximately $9,819,972, excluding brokerage commissions. The aggregate purchase price of the 144,322 Shares beneficially owned by Starboard C LP is approximately $7,303,386, excluding brokerage commissions. The aggregate purchase price of the 100,784 Shares beneficially owned by Starboard L Master is approximately $5,099,741, excluding brokerage commissions. The aggregate purchase price of the 381,415 Shares beneficially owned by Starboard X Master is approximately $19,335,681, excluding brokerage commissions. The aggregate purchase price of the 320,896 Shares held in the Starboard Value LP Account is approximately $16,738,179, excluding brokerage commissions.

Item 5.

Interest in Securities of the Issuer.

Item 5 is hereby amended and restated to read as follows:

The aggregate percentage of Shares reported owned by each person named herein is based upon 58,190,096 Shares outstanding, as of April 30, 2023, which is the total number of Shares outstanding as reported in the Issuer’s Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on May 9, 2023.

Starboard V&O Fund

(a)

As of the close of business on June 14, 2023 Starboard V&O Fund beneficially owned 1,518,803 Shares.

Percentage: Approximately 2.6%

(b)

1. Sole power to vote or direct vote: 1,518,803

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 1,518,803
4. Shared power to dispose or direct the disposition: 0

(c)

The transactions in the Shares by Starboard V&O Fund during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

CUSIP No. 589378108

Starboard S LLC

(a)

As of the close of business on June 14, 2023, Starboard S LLC beneficially owned 194,038 Shares.

Percentage: Less than 1%

(b)

1. Sole power to vote or direct vote: 194,038

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 194,038
4. Shared power to dispose or direct the disposition: 0

(c)

The transactions in the Shares by Starboard S LLC during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Starboard C LP

(a)

As of the close of business on June 14, 2023, Starboard C LP beneficially owned 144,322 Shares.

Percentage: Less than 1%

(b)

1. Sole power to vote or direct vote: 144,322

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 144,322
4. Shared power to dispose or direct the disposition: 0

(c)

The transactions in the Shares by Starboard C LP during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Starboard R LP

(a)

Starboard R LP, as the general partner of Starboard C LP, may be deemed the beneficial owner of the 144,322 Shares owned by Starboard C LP.

Percentage: Less than 1%

(b)

1. Sole power to vote or direct vote: 144,322

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 144,322
4. Shared power to dispose or direct the disposition: 0

(c)

Starboard R LP has not entered into any transactions in the Shares during the past sixty days. The transactions in the Shares on behalf of Starboard C LP during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Starboard L Master

(a)

As of the close of business on June 14, 2023, Starboard L Master beneficially owned 100,784 Shares.

Percentage: Less than 1%

CUSIP No. 589378108

(b)

1. Sole power to vote or direct vote: 100,784

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 100,784
4. Shared power to dispose or direct the disposition: 0

(c)

The transactions in the Shares by Starboard L Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Starboard L GP

(a)

Starboard L GP, as the general partner of Starboard L Master, may be deemed the beneficial owner of the 100,784 Shares owned by Starboard L Master.

Percentage: Less than 1%

(b)

1. Sole power to vote or direct vote: 100,784

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 100,784
4. Shared power to dispose or direct the disposition: 0

(c)

Starboard L GP has not entered into any transactions in the Shares during the past sixty days. The transactions in the Shares on behalf of Starboard L Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Starboard R GP

(a)

Starboard R GP, as the general partner of Starboard R LP and Starboard L GP, may be deemed the beneficial owner of the (i) 144,322 Shares owned by Starboard C LP, and (ii) 100,784 Shares owned by Starboard L Master.

Percentage: Less than 1%

(b)

1. Sole power to vote or direct vote: 245,106

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 245,106
4. Shared power to dispose or direct the disposition: 0

(c)

Starboard R GP has not entered into any transactions in the Shares during the past sixty days. The transactions in the Shares on behalf of each of Starboard C LP and Starboard L Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Starboard X Master

(a)

As of the close of business on June 14, 2023, Starboard X Master beneficially owned 381,415 Shares.

Percentage: Less than 1%

CUSIP No. 589378108

(b)

1. Sole power to vote or direct vote: 381,415

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 381,415
4. Shared power to dispose or direct the disposition: 0

(c)

The transactions in the Shares by Starboard X Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Starboard Value LP

(a)

As of the close of business on June 14, 2023, 320,896 Shares were held in the Starboard Value LP Account. Starboard Value LP, as the investment manager of Starboard V&O Fund, Starboard C LP, Starboard L Master, Starboard X Master and the Starboard Value LP Account and the manager of Starboard S LLC, may be deemed the beneficial owner of the (i) 1,518,803 Shares owned by Starboard V&O Fund, (ii) 194,038 Shares owned by Starboard S LLC, (iii) 144,322 Shares owned by Starboard C LP, (iv) 100,784 Shares owned by Starboard L Master, (v) 381,415 Shares owned by Starboard X Master, and (vi) 320,896 Shares held in the Starboard Value LP Account.

Percentage: Approximately 4.6%

(b)

1. Sole power to vote or direct vote: 2,660,258

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 2,660,258

4. Shared power to dispose or direct the disposition: 0

(c)

The transactions in the Shares by Starboard Value LP through the Starboard Value LP Account and on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP, Starboard L Master and Starboard X Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Starboard Value GP

(a)

Starboard Value GP, as the general partner of Starboard Value LP, may be deemed the beneficial owner of the (i) 1,518,803 Shares owned by Starboard V&O Fund, (ii) 194,038 Shares owned by Starboard S LLC, (iii) 144,322 Shares owned by Starboard C LP, (iv) 100,784 Shares owned by Starboard L Master, (v) 381,415 Shares owned by Starboard X Master, and (vi) 320,896 Shares held in the Starboard Value LP Account.

Percentage: Approximately 4.6%

(b)

1. Sole power to vote or direct vote: 2,660,258

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 2,660,258
4. Shared power to dispose or direct the disposition: 0

(c)

Starboard Value GP has not entered into any transactions in the Shares during the past sixty days. The transactions in the Shares by Starboard Value LP through the Starboard Value LP Account and on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP, Starboard L Master and Starboard X Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

CUSIP No. 589378108

Principal Co

(a)

Principal Co, as a member of Starboard Value GP, may be deemed the beneficial owner of the (i) 1,518,803 Shares owned by Starboard V&O Fund, (ii) 194,038 Shares owned by Starboard S LLC, (iii) 144,322 Shares owned by Starboard C LP, (iv) 100,784 Shares owned by Starboard L Master, (v) 381,415 Shares owned by Starboard X Master, and (vi) 320,896 Shares held in the Starboard Value LP Account.

Percentage: Approximately 4.6%

(b)

1. Sole power to vote or direct vote: 2,660,258

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 2,660,258
4. Shared power to dispose or direct the disposition: 0

(c)

Principal Co has not entered into any transactions in the Shares during the past sixty days. The transactions in the Shares by Starboard Value LP through the Starboard Value LP Account and on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP, Starboard L Master and Starboard X Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Principal GP

(a)

Principal GP, as the general partner of Principal Co, may be deemed the beneficial owner of the (i) 1,518,803 Shares owned by Starboard V&O Fund, (ii) 194,038 Shares owned by Starboard S LLC, (iii) 144,322 Shares owned by Starboard C LP, (iv) 100,784 Shares owned by Starboard L Master, (v) 381,415 Shares owned by Starboard X Master, and (vi) 320,896 Shares held in the Starboard Value LP Account.

Percentage: Approximately 4.6%

(b)

1. Sole power to vote or direct vote: 2,660,258

2. Shared power to vote or direct vote: 0
3. Sole power to dispose or direct the disposition: 2,660,258
4. Shared power to dispose or direct the disposition: 0

(c)

Principal GP has not entered into any transactions in the Shares during the past sixty days. The transactions in the Shares by Starboard Value LP through the Starboard Value LP Account and on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP, Starboard L Master and Starboard X Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

Messrs. Smith and Feld

(a)

Each of Messrs. Smith and Feld, as a member of Principal GP and as a member of each of the Management Committee of Starboard Value GP and the Management Committee of Principal GP, may be deemed the beneficial owner of the (i) 1,518,803 Shares owned by Starboard V&O Fund, (ii) 194,038 Shares owned by Starboard S LLC, (iii) 144,322 Shares owned by Starboard C LP, (iv) 100,784 Shares owned by Starboard L Master, (v) 381,415 Shares owned by Starboard X Master, and (vi) 320,896 Shares held in the Starboard Value LP Account.

CUSIP No. 589378108

Percentage: Approximately 4.6%

(b)

1. Sole power to vote or direct vote: 0

2. Shared power to vote or direct vote: 2,660,258
3. Sole power to dispose or direct the disposition: 0
4. Shared power to dispose or direct the disposition: 2,660,258

(c)

None of Messrs. Smith or Feld has entered into any transactions in the Shares during the past sixty days. The transactions in the Shares by Starboard Value LP through the Starboard Value LP Account and on behalf of each of Starboard V&O Fund, Starboard S LLC, Starboard C LP, Starboard L Master, and Starboard X Master during the past sixty days are set forth in Schedule A and are incorporated herein by reference.

The filing of this Schedule 13D shall not be deemed an admission that the Reporting Persons are, for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, the beneficial owners of any securities of the Issuer that he or it does not directly own. Each of the Reporting Persons specifically disclaims beneficial ownership of the securities reported herein that he or it does not directly own.

(d)

No person other than the Reporting Persons is known to have the right to receive, or the power to direct the receipt of dividends from, or proceeds from the sale of, the Shares.

(e)

As of June 13, 2023, the Reporting Persons ceased to beneficially own more than 5% of the outstanding Shares of the Issuer.

CUSIP No. 589378108

SIGNATURES

After reasonable inquiry and to the best of his knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated: June 15, 2023

STARBOARD VALUE AND OPPORTUNITY MASTER FUND LTD

By: Starboard Value LP,

its investment manager

STARBOARD VALUE AND OPPORTUNITY S LLC

By: Starboard Value LP,

its manager

STARBOARD VALUE AND OPPORTUNITY C LP

By: Starboard Value R LP,

its general partner

STARBOARD VALUE R LP

By: Starboard Value R GP LLC,

its general partner

STARBOARD VALUE AND OPPORTUNITY MASTER FUND L LP

By: Starboard Value L LP,

its general partner

STARBOARD VALUE L LP

By: Starboard Value R GP LLC,

its general partner

STARBOARD X MASTER FUND LTD

By: Starboard Value LP,

its investment manager

STARBOARD VALUE LP

By: Starboard Value GP LLC,

its general partner

STARBOARD VALUE GP LLC

By: Starboard Principal Co LP,

its member

STARBOARD PRINCIPAL CO LP

By: Starboard Principal Co GP LLC,

its general partner

STARBOARD PRINCIPAL CO GP LLC

STARBOARD VALUE R GP LLC

By:	/s/ Jeffrey C. Smith
	Name:	Jeffrey C. Smith
	Title:	Authorized Signatory

/s/ Jeffrey C. Smith

JEFFREY C. SMITH

Individually and as attorney-in-fact for Peter A. Feld

CUSIP No. 589378108

SCHEDULE A

Transactions in the Shares During the Past Sixty Days

Nature of the Transaction

Amount of Securities

(Sold)

Price ($)

Date of

Sale

STARBOARD VALUE AND OPPORTUNITY MASTER FUND LTD

Sale of Common Stock	(3,974)	42.2785	06/06/2023
Sale of Common Stock	(14,273)	42.0076	06/06/2023
Sale of Common Stock	(188)	42.1306	06/07/2023
Sale of Common Stock	(38,823)	42.2080	06/07/2023
Sale of Common Stock	(30,224)	43.1949	06/12/2023
Sale of Common Stock	(16,622)	42.4916	06/13/2023
Sale of Common Stock	(399,646)	41.5000	06/13/2023
Sale of Common Stock	(41,599)	42.1349	06/13/2023
Sale of Common Stock	(51,923)	40.9466	06/14/2023
Sale of Common Stock	(15,929)	40.9157	06/14/2023
Sale of Common Stock	(21,685)	40.7831	06/14/2023

STARBOARD VALUE AND OPPORTUNITY S LLC

Sale of Common Stock	(508)	42.2785	06/06/2023
Sale of Common Stock	(1,824)	42.0076	06/06/2023
Sale of Common Stock	(24)	42.1306	06/07/2023
Sale of Common Stock	(4,959)	42.2080	06/07/2023
Sale of Common Stock	(3,861)	43.1949	06/12/2023
Sale of Common Stock	(2,124)	42.4916	06/13/2023
Sale of Common Stock	(51,058)	41.5000	06/13/2023
Sale of Common Stock	(5,314)	42.1349	06/13/2023
Sale of Common Stock	(6,633)	40.9466	06/14/2023
Sale of Common Stock	(2,035)	40.9157	06/14/2023
Sale of Common Stock	(2,770)	40.7831	06/14/2023

STARBOARD VALUE AND OPPORTUNITY C LP

Sale of Common Stock	(377)	42.2785	06/06/2023
Sale of Common Stock	(1,356)	42.0076	06/06/2023
Sale of Common Stock	(18)	42.1306	06/07/2023
Sale of Common Stock	(3,690)	42.2080	06/07/2023
Sale of Common Stock	(2,872)	43.1949	06/12/2023
Sale of Common Stock	(1,580)	42.4916	06/13/2023
Sale of Common Stock	(37,976)	41.5000	06/13/2023
Sale of Common Stock	(3,953)	42.1349	06/13/2023
Sale of Common Stock	(4,934)	40.9466	06/14/2023
Sale of Common Stock	(1,514)	40.9157	06/14/2023
Sale of Common Stock	(2,060)	40.7831	06/14/2023

CUSIP No. 589378108

STARBOARD VALUE AND OPPORTUNITY MASTER FUND L LP

Sale of Common Stock	(264)	42.2785	06/06/2023
Sale of Common Stock	(947)	42.0076	06/06/2023
Sale of Common Stock	(13)	42.1306	06/07/2023
Sale of Common Stock	(2,576)	42.2080	06/07/2023
Sale of Common Stock	(2,005)	43.1949	06/12/2023
Sale of Common Stock	(1,103)	42.4916	06/13/2023
Sale of Common Stock	(26,519)	41.5000	06/13/2023
Sale of Common Stock	(2,760)	42.1349	06/13/2023
Sale of Common Stock	(3,446)	40.9466	06/14/2023
Sale of Common Stock	(1,057)	40.9157	06/14/2023
Sale of Common Stock	(1,439)	40.7831	06/14/2023

STARBOARD X MASTER FUND LTD

Sale of Common Stock	(998)	42.2785	06/06/2023
Sale of Common Stock	(3,584)	42.0076	06/06/2023
Sale of Common Stock	(47)	42.1306	06/07/2023
Sale of Common Stock	(9,750)	42.2080	06/07/2023
Sale of Common Stock	(7,590)	43.1949	06/12/2023
Sale of Common Stock	(4,174)	42.4916	06/13/2023
Sale of Common Stock	(100,363)	41.5000	06/13/2023
Sale of Common Stock	(10,447)	42.1349	06/13/2023
Sale of Common Stock	(13,039)	40.9466	06/14/2023
Sale of Common Stock	(4,000)	40.9157	06/14/2023
Sale of Common Stock	(5,446)	40.7831	06/14/2023

STARBOARD VALUE LP

(Through the Starboard Value LP Account)

Sale of Common Stock	(840)	42.2785	06/06/2023
Sale of Common Stock	(3,016)	42.0076	06/06/2023
Sale of Common Stock	(40)	42.1306	06/07/2023
Sale of Common Stock	(8,202)	42.2080	06/07/2023
Sale of Common Stock	(6,386)	43.1949	06/12/2023
Sale of Common Stock	(3,512)	42.4916	06/13/2023
Sale of Common Stock	(84,438)	41.5000	06/13/2023
Sale of Common Stock	(8,789)	42.1349	06/13/2023
Sale of Common Stock	(10,970)	40.9466	06/14/2023
Sale of Common Stock	(3,365)	40.9157	06/14/2023
Sale of Common Stock	(4,582)	40.7831	06/14/2023

SEC Form SC 13D/A filed by Mercury Systems Inc (Amendment)