Director at Mercury Systems (MRCY) awarded 474 deferred stock units

Rhea-AI Filing Summary

Mercury Systems director Barry R. Nearhos reported receiving additional equity-based compensation. On January 15, 2026, he was granted 474 deferred stock units (DSUs), recorded as an acquisition of common stock at $0 per share in lieu of a quarterly cash retainer for board service. These DSUs are fully vested on the grant date but will not convert into shares of common stock until he ceases to serve on the Board of Directors.

Following this grant, Nearhos is shown as beneficially owning 31,079 shares of common stock directly, plus an additional 3,500 shares indirectly held by his spouse. The filing reflects routine director compensation and updated ownership totals rather than any open-market purchase or sale.

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).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Nearhos Barry R

(Last) (First) (Middle)

50 MINUTEMAN ROAD

(Street)

ANDOVER MA 01810

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MERCURY SYSTEMS INC [ MRCY ]

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)
01/15/2026

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	01/15/2026		A		474(1)	A	$0	31,079	D
Common Stock								3,500	I	By Spouse

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 deferred stock units (DSUs) issued in lieu of a quarterly cash retainer payment for service as a director. These DSUs were fully vested upon grant, but do not convert into shares of common stock until the date on which the reporting person ceases to be a member of our Board of Directors.

	/s/ Douglas Munro, attorney-in-fact	01/20/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Mercury Systems (MRCY) report for Barry R. Nearhos?

On January 15, 2026, director Barry R. Nearhos reported an acquisition of 474 deferred stock units (DSUs), recorded as common stock at $0 per share, as part of his director compensation.

Why did Mercury Systems (MRCY) grant 474 DSUs to its director?

The 474 DSUs were issued in lieu of a quarterly cash retainer payment for Nearhos’s service as a director, providing equity-based compensation instead of cash.

When do Barry R. Nearhos’s DSUs at Mercury Systems (MRCY) convert into common stock?

The DSUs are fully vested upon grant but do not convert into shares of common stock until the date when Nearhos ceases to be a member of the Board of Directors.

How many Mercury Systems (MRCY) shares does Barry R. Nearhos beneficially own after this Form 4?

After the reported transaction, Nearhos beneficially owns 31,079 shares of common stock directly and 3,500 shares indirectly, with the indirect shares held by his spouse.

Was there any sale of Mercury Systems (MRCY) stock by Barry R. Nearhos in this filing?

No sale is reported. The Form 4 shows an acquisition of 474 DSUs for director compensation and updates to his direct and indirect beneficial ownership totals.

What role does Barry R. Nearhos hold at Mercury Systems (MRCY)?

Barry R. Nearhos is reported as a director of Mercury Systems and the Form 4 reflects equity compensation related to his board service.