[Form 4] Mercury Systems Inc. Insider Trading Activity

Rhea-AI Filing Summary

Stuart Kupinsky, EVP, Chief Legal Officer and Corporate Secretary of Mercury Systems, reported an insider acquisition on 08/15/2025. He was granted 9,865 restricted stock units (RSUs) at $0 per unit, which represent equity compensation that vests in equal annual increments over three years. After the grant, Mr. Kupinsky beneficially owns 72,699 shares directly and 1,008 shares indirectly through a 401(k) plan. The Form 4 was signed by an attorney-in-fact on 08/19/2025. No derivative transactions or cash purchases were reported.

Positive

• Increased insider ownership: Reporting person’s direct holdings rose to 72,699 shares
• Transparent disclosure: Grant and vesting schedule (3-year equal annual increments) are explicitly stated
• Non-cash compensation alignment: RSUs vesting over time aligns executive incentives with long-term performance

Negative

• None.

Insights

Financial Analyst

TL;DR: Routine executive equity grant increases insider ownership without cash outlay; consistent with compensation vesting schedules.

The reported grant of 9,865 RSUs at no cash price is a non-cash, time-based compensation event. Vesting in equal annual installments over three years aligns the executive's interests with shareholder outcomes over a multi-year horizon. The transaction increases the reporting person’s direct ownership to 72,699 shares, a metric investors can use to track insider alignment. No options, sales, or exercises were disclosed, and there are no indications of unusual trading.

Corporate Governance Expert

TL;DR: Standard equity grant for an executive officer; disclosure is complete and timely per Form 4 requirements.

The filing documents a time-vesting RSU award and clearly states the vesting schedule in the explanatory note. Reporting identifies the filer’s role as EVP, CLO & Corporate Secretary and discloses indirect holdings via a 401(k). The Form 4 was executed by an attorney-in-fact, with signature dated 08/19/2025, satisfying procedural formalities. No governance red flags or departures are evident from the content provided.

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

OMB APPROVAL

OMB Number:			3235-0287
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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^*

KUPINSKY STUART

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, CLO & Corp Sec

3. Date of Earliest Transaction (Month/Day/Year)
08/15/2025

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	08/15/2025		A		9,865(1)	A	$0	72,699	D
Common Stock								1,008	I	401K Plan

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 that vest in equal annual increments over the three-year period following the grant date.

	/s/ Douglas Munro, attorney-in-fact	08/19/2025
	** 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 transaction did Stuart Kupinsky report on Form 4 for MRCY?

He reported the grant of 9,865 restricted stock units (RSUs) on 08/15/2025 at a price of $0 per unit.

How do the RSUs granted to the MRCY executive vest?

The RSUs vest in equal annual increments over three years following the grant date, per the filing's explanatory note.

How many MRCY shares does the reporting person beneficially own after the transaction?

Following the reported grant, he beneficially owns 72,699 shares directly and 1,008 shares indirectly through a 401(k) plan.

Was any cash paid for the securities reported in the Form 4?

No cash was paid; the reported RSUs show a $0 price in the filing.

When was the Form 4 signed and by whom?

The form was signed by an attorney-in-fact, /s/ Douglas Munro, with a signature date of 08/19/2025.