[Form 4] Mercury Systems Inc. Insider Trading Activity

Rhea-AI Filing Summary

William L. Ballhaus, Chairman, President & CEO of Mercury Systems (MRCY), reported sales of common stock on 08/18/2025 and 08/19/2025 under a sell-to-cover program to satisfy tax withholding upon vesting of stock awards. The filing lists a sale of 10,395 shares at an attributed price of $66.5163 on 08/18/2025 and a sale of 13,050 shares at $64.464 on 08/19/2025. Following the transactions the Form 4 shows direct beneficial ownership figures of 388,026.325 shares (after the 08/18 sale) and 374,976.325 shares (after the 08/19 sale), plus indirect holdings of 1,156 shares in a 401(k) plan and 7,066.173 shares held by Milestone Road Holdings, LLC. The Form is signed by an attorney-in-fact on 08/20/2025 and includes an explanation that the sales were executed to satisfy tax withholding obligations.

Positive

• Discloses sell-to-cover sales explicitly, clarifying the purpose of the transactions
• Provides detailed post-transaction beneficial ownership including direct and indirect holdings
• Signed and dated filing indicating formal submission on 08/20/2025

Negative

• Reduction in direct beneficial ownership due to sales of 10,395 and 13,050 shares on 08/18 and 08/19/2025
• Insider sales occurred within a short timeframe (two consecutive days), which may attract investor attention despite being for tax withholding

Insights

Corporate Governance Expert

TL;DR: Routine insider sell-to-cover transactions disclosed by the CEO; no new governance issues disclosed.

The Form 4 documents that William L. Ballhaus, serving as Chairman, President and CEO, executed scheduled sell-to-cover transactions tied to vesting awards. These sales are routine tax-withholding mechanics rather than open-market discretionary disposals based on the disclosure. The filing also identifies modest indirect holdings through a 401(k) and an entity, which clarifies beneficial ownership structure. No departures, option grants, or special arrangements are reported in this Form 4.

Securities Analyst

TL;DR: Insider sales were small relative to total shares outstanding and explicitly for tax withholding; the disclosure is informational and not material on its face.

The report shows sales of 10,395 shares at $66.5163 and 13,050 shares at $64.464 as part of a sell-to-cover program. The filing quantifies post-transaction direct ownership and discloses indirect holdings, improving transparency about the CEO's stake. The document does not report additional derivative activity or other transactions that would materially change dilution or control.

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^*

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)
08/18/2025

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		10,395(1)	D	$66.5163(2)	388,026.325	D
Common Stock	08/19/2025		S		13,050(1)	D	$64.464(2)	374,976.325	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 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 did William L. Ballhaus report on the MRCY Form 4?

He reported sales of 10,395 shares at $66.5163 on 08/18/2025 and 13,050 shares at $64.464 on 08/19/2025 as part of a sell-to-cover program.

Why were the shares sold according to the Form 4 for MRCY?

The filing states the sales were executed to satisfy tax withholding obligations upon the vesting of stock awards.

How many shares does the CEO beneficially own after the reported transactions?

The Form 4 shows direct beneficial ownership figures of 388,026.325 shares (after the 08/18 sale) and 374,976.325 shares (after the 08/19 sale), plus indirect holdings of 1,156 shares (401K) and 7,066.173 shares (Milestone Road Holdings, LLC).

When was the Form 4 signed and filed?

The Form 4 is signed by an attorney-in-fact on 08/20/2025.

Did the Form 4 report any derivative transactions or new grants for MRCY?

No. Table II (derivative securities) contains no reported transactions in this filing.