[Form 4] Mercury Systems Inc. Insider Trading Activity

Rhea-AI Filing Summary

Douglas Munro, Vice President and Chief Accounting Officer of Mercury Systems, reported two open-market sales of the issuer's common stock executed as sell-to-cover transactions to satisfy tax withholding on vested awards. On 08/18/2025 he sold 363 shares at a per-share price of $66.5163, leaving him with 16,450 shares beneficially owned after that transaction. On 08/19/2025 he sold 376 shares at $64.464, leaving 16,074 shares beneficially owned after that sale.

The filing also notes indirect ownership through a 401(k) plan and is signed by Mr. Munro on 08/20/2025. The disclosures identify the transactions as tax-related sell-to-cover sales and report direct ownership counts following each sale.

Positive

• Clear disclosure of sell-to-cover transactions with per-share prices and post-transaction holdings
• Compliance with Section 16 reporting: signed Form 4 with transaction dates and role identified
• Identification of indirect ownership through a 401(k) plan

Negative

• Insider sales reduced direct holdings by 739 shares over two days (08/18 and 08/19/2025)

Insights

Financial Analyst

TL;DR: Insider sales were routine sell-to-cover transactions tied to award vesting, reducing direct holdings by 739 shares over two days.

The transactions are explicitly described as sell-to-cover for tax withholding, indicating they were not discretionary cash sales to raise funds but mechanically tied to equity award vesting. The two sales totaled 739 shares at weighted-average prices near the mid-$60s, leaving direct beneficial ownership of 16,074 shares after the second sale. This is a straightforward Section 16 disclosure with clear post-transaction holdings and a noted indirect holding via a 401(k) plan.

Corporate Governance Expert

TL;DR: Filing shows timely, appropriately labeled insider reporting of award-related share dispositions; documentation appears compliant.

The Form 4 clearly marks the transactions as sell-to-cover and provides per-share prices and post-transaction holdings, satisfying Section 16 reporting requirements. The signature and dates are present and the filing lists the reporting person’s role as VP, CAO. There is no indication in the document of other compensatory or opportunistic sales; the presence of an indirect 401(k) holding is disclosed. From a governance perspective, disclosure is complete within the form's scope.

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^*

Munro Douglas

(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)
	VP, CAO

3. Date of Earliest Transaction (Month/Day/Year)
08/18/2025

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	08/18/2025		S		363(1)	D	$66.5163(2)	16,450	D
Common Stock	08/19/2025		S		376(1)	D	$64.464(2)	16,074	D
Common Stock								99	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 shares sold as part of a sell-to-cover program to satisfy tax withholding obligations upon the vesting of stock awards.

2. Represents the per share price attributed to sales of shares on behalf of all participants under the sell-to-cover program on the transaction date indicated.

	/s/ Douglas Munro	08/20/2025
	** 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 Douglas Munro report in the Form 4 for MRCY?

He reported two sell-to-cover sales of Mercury Systems common stock: 363 shares at $66.5163 on 08/18/2025 and 376 shares at $64.464 on 08/19/2025.

How many shares does the reporting person own after the reported transactions?

The filing shows 16,450 shares beneficially owned after the 08/18/2025 sale and 16,074 shares after the 08/19/2025 sale.

Why were the shares sold according to the Form 4?

The explanation states the shares were sold as part of a sell-to-cover program to satisfy tax withholding obligations upon vesting of stock awards.

Did the Form 4 disclose any indirect holdings for the reporting person?

Yes, the filing discloses indirect ownership via a 401(k) plan.

When was the Form 4 signed?

The filing is signed by Douglas Munro on 08/20/2025.