[Form 4] Mercury Systems Inc. Insider Trading Activity

Rhea-AI Filing Summary

Stuart Kupinsky, EVP, CLO & Corporate Secretary of Mercury Systems (MRCY), reported routine sales of company stock to cover tax withholding upon vesting. The Form 4 shows he sold 1,182 shares on 08/18/2025 at $66.5163 per share and 1,220 shares on 08/19/2025 at $64.464 per share as part of a sell-to-cover program. After those sales his direct beneficial ownership is reported as 70,297 shares. He also holds 1,008 shares indirectly through a 401(k) plan. The filing is signed by an attorney-in-fact on 08/20/2025 and includes an explanation that the sales satisfied tax withholding obligations related to vested awards.

Positive

• Timely disclosure of insider transactions with transaction dates and prices provided
• Clear explanation that sales were part of a sell-to-cover program to satisfy tax withholding
• Remaining ownership disclosed including direct and indirect holdings (70,297 direct; 1,008 indirect via 401(k))

Negative

• None.

Insights

Financial Analyst

TL;DR: Insider sold shares via sell-to-cover to satisfy tax withholding; transactions appear routine and non-dispositive.

The reported disposals total 2,402 shares across two dates with per-share prices of $66.5163 and $64.464. The filing attributes these to a sell-to-cover program tied to vesting of equity awards, which is a common administrative action that does not indicate a change in ownership intent. Remaining direct beneficial ownership is 70,297 shares with an additional 1,008 held indirectly in a 401(k) plan. No derivative transactions or additional compensatory grants are reported on this Form 4.

Corporate Governance Expert

TL;DR: Disclosure is complete for the reported transactions and consistent with routine withholding practices.

The Form 4 clearly states the relationship of the reporting person to the issuer and provides per-share prices and share counts for each transaction. The explanatory note clarifies the sell-to-cover nature of the sales, which typically pose limited governance concerns when promptly disclosed. Signature by an attorney-in-fact is indicated and dated 08/20/2025. No red flags such as large, unexplained disposals or trading outside of a stated plan are present in the filing content.

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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hours per response:			0.5

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)
08/18/2025

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		1,182(1)	D	$66.5163(2)	71,517	D
Common Stock	08/19/2025		S		1,220(1)	D	$64.464(2)	70,297	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 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, attorney-in-fact	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 insider transactions did Stuart Kupinsky report for MRCY?

He reported sales of 1,182 shares on 08/18/2025 at $66.5163 and 1,220 shares on 08/19/2025 at $64.464, executed as sell-to-cover transactions.

Why were the MRCY shares sold by the reporting person?

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

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

The Form 4 reports 70,297 shares owned directly after the transactions and 1,008 shares indirectly held through a 401(k) plan.

When was this Form 4 signed?

The signature block shows the form was signed by an attorney-in-fact on 08/20/2025.

Did the Form 4 report any derivative transactions or option exercises?

No. The filing lists only non-derivative common stock sales and an indirect 401(k) holding; no derivative securities are reported.