[Form 4] Mercury Systems Inc. Insider Trading Activity

Rhea-AI Filing Summary

Steven Ratner, Executive Vice President and CHRO of Mercury Systems Inc. (MRCY), reported two sales of common stock executed as part of a sell-to-cover program to satisfy tax withholding on vested awards. On 08/18/2025 he sold 1,681 shares at $66.5163 per share, leaving 42,536 shares owned directly; on 08/19/2025 he sold 1,735 shares at $64.464 per share, leaving 40,801 shares owned directly. The filing also shows an indirect beneficial ownership of 81 shares held in a 401(k) plan. The seller certified these sales were to cover tax withholding obligations arising from vesting stock awards.

Positive

• Transparent disclosure of sell-to-cover transactions and per-share prices
• Sales labeled as tax-withholding, indicating routine administration of vested awards
• Updated direct ownership figures provided after each transaction

Negative

• Reduction in direct holdings of 3,416 shares following the two reported sales

Insights

Financial Analyst

TL;DR: Routine insider sell-to-cover transactions; modest reduction in direct holdings with no disclosed change to employment or control.

These transactions are described as sell-to-cover shares to satisfy tax withholding on vested awards, which is a common, non-dispositive insider liquidity event. The two sales total 3,416 shares across two days at prices of $66.5163 and $64.464. Post-transaction direct ownership figures are reported as 42,536 and 40,801, indicating the filings show the updated share counts after each sale. Absent additional context on total outstanding shares or planned future sales, this filing alone is unlikely to be material to Mercury Systems' valuation.

Corporate Governance Expert

TL;DR: Proper disclosure of sell-to-cover tax withholding is corporate-governance compliant and reduces risk of reporting irregularities.

The Form 4 identifies the reporting person as an officer (EVP, CHRO) and documents that sales were executed under a sell-to-cover program to meet tax obligations from vested equity awards. The filing was signed by an attorney-in-fact, consistent with authorized reporting practice. These actions reflect routine equity compensation administration rather than any governance concern such as unexpected departures or opportunistic insider selling.

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
Estimated average burden
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^*

Ratner Steven

(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, CHRO

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		1,681(1)	D	$66.5163(2)	42,536	D
Common Stock	08/19/2025		S		1,735(1)	D	$64.464(2)	40,801	D
Common Stock								81	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 transactions did Steven Ratner report for MRCY?

He reported two sell-to-cover sales: 1,681 shares on 08/18/2025 at $66.5163 and 1,735 shares on 08/19/2025 at $64.464.

Why were the shares sold according to the Form 4?

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

How many shares does Steven Ratner beneficially own after the reported transactions?

The filing shows direct beneficial ownership figures of 42,536 shares after the 08/18/2025 sale and 40,801 shares after the 08/19/2025 sale; plus 81 shares indirect via a 401(k) plan.

Do these Form 4 transactions indicate a change in Steven Ratner’s role at Mercury Systems?

No role change is disclosed; the filing identifies him as an EVP, CHRO and does not report any change in position.

Who signed the Form 4 on behalf of the reporting person?

The form was signed by Douglas Munro, attorney-in-fact, as indicated in the filing.