[Form 4] Mercury Systems Inc. Insider Trading Activity

Rhea-AI Filing Summary

William L. Ballhaus, Chairman, President & CEO of Mercury Systems, reported an insider grant dated 08/15/2025. The filing shows 44,940 restricted stock units (RSUs) were acquired at $0, and these RSUs vest in equal annual increments over the three years following the grant date. After the transaction, Ballhaus beneficially owns 398,421.325 shares directly, plus 1,156 shares indirectly via a 401(k) plan and 7,066.173 shares indirectly through Milestone Road Holdings, LLC. The Form 4 was signed on behalf of the reporting person by an attorney-in-fact on 08/19/2025.

Insights

Financial Analyst

TL;DR: A routine executive equity grant of 44,940 RSUs aligns CEO compensation with shareholder value without immediate cash cost.

This grant represents compensation delivered as restricted stock units that vest over three years, which typically serves to align the CEO's incentives with long-term shareholder outcomes and retention. The acquisition price of $0 indicates these are compensation awards rather than open-market purchases. The reported total beneficial ownership remains substantial at 398,421.325 shares directly, with additional indirect holdings through retirement and entity structures.

Corporate Governance Expert

TL;DR: Standard time-based RSU award for a CEO; governance signal is retention and alignment, not a market transaction.

Time-based RSUs vesting annually over three years are a common governance tool to encourage multi-year stewardship. Because the filing discloses the award but not performance-contingent terms, this appears to be a simple retention and alignment grant rather than a performance incentive. The filing follows required disclosure practices and lists indirect ownership via a 401(k) and an affiliated holding vehicle.

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^*

Ballhaus William L

(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
X	Officer (give title below)		Other (specify below)
	Chairman, President & CEO

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		44,940(1)	A	$0	398,421.325	D
Common Stock								1,156	I	401K Plan
Common Stock								7,066.173	I	By Milestone Road Holdings, LLC

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 did Mercury Systems (MRCY) CEO William Ballhaus receive on 08/15/2025?

He was granted 44,940 restricted stock units (RSUs) that vest in equal annual increments over three years.

Did William Ballhaus pay for the RSUs reported in the Form 4 for MRCY?

No; the transaction price is reported as $0, indicating these RSUs were granted as compensation.

How many MRCY shares does Ballhaus beneficially own after the reported transaction?

He beneficially owns 398,421.325 shares directly, plus 1,156 shares via a 401(k) plan and 7,066.173 shares via Milestone Road Holdings, LLC.

When was the Form 4 for this MRCY transaction signed?

The Form 4 was signed by an attorney-in-fact on 08/19/2025.

How do the RSUs vest according to the filing?

The filing explains the RSUs vest in equal annual increments over three years following the grant date.