Mercury Systems officer sells 1,308 shares for taxes

MERCURY SYSTEMS INC (MRCY) reported that officer Stuart Kupinsky, EVP, CLO & Corp Sec, had 1,308 shares of common stock sold on 2026-08-19 under a sell-to-cover program to satisfy tax withholding obligations upon vesting of stock awards.

Rhea-AI Filing Summary

MERCURY SYSTEMS INC (MRCY) reported that officer Stuart Kupinsky, EVP, CLO & Corp Sec, had 1,308 shares of common stock sold on 2026-08-19 under a sell-to-cover program to satisfy tax withholding obligations upon vesting of stock awards. The program price for participants that day was $100.306 per share. After this tax-related sale, Kupinsky held 57,352 shares directly and 1,233 shares indirectly through a 401K Plan.

Insider Trade Summary

Net Seller: 1,308 shares

Net Sell 2 txns

Insider KUPINSKY STUART

Role EVP, CLO & Corp Sec

Sold 1,308 shs ($131K)

Type	Security	Shares	Price	Value
Sale	Common Stock F1, F2	1,308	$100.306	$131K
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 57,352 shares (Direct); Common Stock — 1,233 shares (Indirect, 401K Plan)

Footnotes (2)

1. F1. Represents shares sold as part of a sell-to-cover program to satisfy tax withholding obligations upon the vesting of stock awards.
2. F2. 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.

Key Figures

Shares sold under sell-to-cover program: 1,308 shares Program price per share: $100.306 per share Direct holdings after transaction: 57,352 shares +1 more

4 metrics

Shares sold under sell-to-cover program 1,308 shares Common Stock sold on 2026-08-19 to satisfy tax withholding obligations

Program price per share $100.306 per share Per share price attributed to sales for all participants on 2026-08-19

Direct holdings after transaction 57,352 shares Common Stock directly held by Stuart Kupinsky following the 2026-08-19 sale

Indirect holdings (401K Plan) after transaction 1,233 shares Common Stock held indirectly through a 401K Plan after the reported date

Key Terms

sell-to-cover program, tax withholding obligations, 401K Plan

3 terms

sell-to-cover program financial

"Represents shares sold as part of a sell-to-cover program to satisfy tax"

tax withholding obligations financial

"program to satisfy tax withholding obligations upon the vesting of stock awards"

401K Plan financial

"Indirect ownership of common stock reported as 401K Plan"

A 401(k) plan is an employer-sponsored retirement savings account that lets workers set aside part of their paycheck into investments, often with tax breaks and sometimes with matching contributions from the employer. Think of it as a workplace piggy bank that grows through employee contributions, optional company top-ups, and market returns; it matters to investors because it shapes household retirement security, drives large flows of money into public markets, and affects a company’s compensation costs and ability to attract and keep talent.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did MRCY report for Stuart Kupinsky on August 19, 2026?

MERCURY SYSTEMS INC (MRCY) reported that Stuart Kupinsky had 1,308 shares of common stock sold on 2026-08-19 under a sell-to-cover program to satisfy tax withholding obligations tied to vested stock awards.

At what price were Stuart Kupinsky’s MRCY shares sold under the sell-to-cover program?

The Form 4 states a per share price of $100.306, representing the price attributed to sales of shares on behalf of all participants in the sell-to-cover program on 2026-08-19.

How many MRCY shares does Stuart Kupinsky hold directly after this transaction?

Following the August 19, 2026 tax-related sale, Stuart Kupinsky is reported as directly holding 57,352 shares of MERCURY SYSTEMS INC common stock.

What indirect MRCY holdings does Stuart Kupinsky report after the transaction?

In addition to his direct holdings, the filing lists an indirect position of 1,233 shares of MERCURY SYSTEMS INC common stock held through a 401K Plan after the reported transaction.

Was the reported MRCY share sale part of a discretionary trade by Stuart Kupinsky?

The Form 4 notes that the 1,308-share sale was part of a sell-to-cover program used to meet tax withholding obligations upon vesting of stock awards, rather than a standalone discretionary sale.

Is the MRCY Form 4 transaction associated with a Rule 10b5-1 trading plan?

The filing’s Rule 10b5-1 checkbox is not marked as an affirmative plan, and the footnotes describe the sale as part of a sell-to-cover program for tax withholding obligations, without identifying a Rule 10b5-1 plan.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 08/21/2026 - 04:51 PM EDT Accepted by SEC EDGAR 08/21/2026 - 04:50 PM EDT Learn about SEC filing dates

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^*

KUPINSKY STUART

(Last) (First) (Middle)

50 MINUTEMAN ROAD

(Street)

ANDOVER MASSACHUSETTS 01810

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
08/19/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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	08/19/2026		S		1,308(1)	D	$100.306(2)	57,352	D
Common Stock								1,233	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	08/21/2026
	** 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.
* Form 4: SEC 1474 (03-26)