Mercury Systems EVP forfeits 6,977 stock awards

Q: What insider transaction did MRCY report for Stuart Kupinsky on this Form 4?

MERCURY SYSTEMS INC reported that Stuart Kupinsky had 6,977 shares of common stock disposed of in a transaction with the issuer. The shares were associated with performance stock awards that were forfeited under their terms.

Q: How many MRCY shares were forfeited by Stuart Kupinsky and why?

Stuart Kupinsky forfeited 6,977 shares of MERCURY SYSTEMS INC common stock. A footnote explains these represented shares underlying performance stock awards that were forfeited as a result of below-target performance under the award criteria.

Q: Was the MRCY insider transaction by Stuart Kupinsky a market sale?

No. The Form 4 describes the transaction as a disposition to the issuer with a per-share price of $0.00. A footnote clarifies it involved forfeited performance stock awards, not an open-market sale.

Q: Did the MRCY Form 4 indicate use of a Rule 10b5-1 trading plan?

No. The Rule 10b5-1 checkbox is marked false for this filing. The transaction relates to forfeited performance stock awards, rather than trades executed under a pre-arranged 10b5-1 trading plan.

MERCURY SYSTEMS INC (MRCY) reported that executive officer Stuart Kupinsky, EVP, CLO & Corp Sec, had 6,977 shares of common stock disposed of in a transaction with the issuer on 2026-08-14.

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)How Sentiment works

Sentiment and the balance of points

Rhea-AI Sentiment reads the wording of the document, how positive or negative its language is on a 1 to 5 scale. The balance of points shown with the takes weighs what the document actually discloses, so the two can disagree, for example when a trial that missed its main goal is described in upbeat language.

How Sentiment works How the balance works

Form Type

Rhea-AI Filing Summary

MERCURY SYSTEMS INC (MRCY) reported that executive officer Stuart Kupinsky, EVP, CLO & Corp Sec, had 6,977 shares of common stock disposed of in a transaction with the issuer on 2026-08-14. According to a footnote, these shares represented performance stock awards that were forfeited due to below-target performance under the award terms. After this forfeiture, Kupinsky directly holds 61,033 shares of MRCY common stock and indirectly holds 1,233 shares through a 401K Plan.

Insider Trade Summary

Disposition: 6,977 shares

Disposition 2 txns

Insider KUPINSKY STUART

Role EVP, CLO & Corp Sec

Type	Security	Shares	Price	Value
Disposition	Common Stock ^F1	6,977	$0.00	$0.00
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 61,033 shares (Direct); Common Stock — 1,233 shares (Indirect, 401K Plan)

Footnotes (1)

F1. Represents shares underlying performance stock awards that were forfeited as a result of below-target performance.

Key Figures

Shares disposed (forfeited PSAs): 6,977 shares Direct holdings after transaction: 61,033 shares Indirect 401K holdings: 1,233 shares +1 more

4 metrics

Shares disposed (forfeited PSAs) 6,977 shares Common stock underlying performance stock awards disposed of to issuer on 2026-08-14

Direct holdings after transaction 61,033 shares Direct MRCY common stock held by Stuart Kupinsky following the forfeiture

Indirect 401K holdings 1,233 shares Indirect MRCY common stock held through a 401K Plan after the transaction

Per-share transaction price $0.00 Reported price per share for the disposition to issuer of forfeited performance awards

Key Terms

performance stock awards, forfeited, Disposition to issuer, 401K Plan

4 terms

performance stock awards financial

"Represents shares underlying performance stock awards that were forfeited"

forfeited financial

"awards that were forfeited as a result of below-target performance"

Disposition to issuer financial

"transaction_code_description":"Disposition to issuer"

401K Plan financial

"nature_of_ownership":"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 this Form 4?

MERCURY SYSTEMS INC reported that Stuart Kupinsky had 6,977 shares of common stock disposed of in a transaction with the issuer. The shares were associated with performance stock awards that were forfeited under their terms.

How many MRCY shares were forfeited by Stuart Kupinsky and why?

Stuart Kupinsky forfeited 6,977 shares of MERCURY SYSTEMS INC common stock. A footnote explains these represented shares underlying performance stock awards that were forfeited as a result of below-target performance under the award criteria.

How many MRCY shares does Stuart Kupinsky hold after this Form 4 transaction?

After the reported forfeiture, Stuart Kupinsky directly holds 61,033 shares of MERCURY SYSTEMS INC common stock. He also indirectly holds 1,233 shares through a 401K Plan, as disclosed in the filing.

Was the MRCY insider transaction by Stuart Kupinsky a market sale?

No. The Form 4 describes the transaction as a disposition to the issuer with a per-share price of $0.00. A footnote clarifies it involved forfeited performance stock awards, not an open-market sale.

Did the MRCY Form 4 indicate use of a Rule 10b5-1 trading plan?

No. The Rule 10b5-1 checkbox is marked false for this filing. The transaction relates to forfeited performance stock awards, rather than trades executed under a pre-arranged 10b5-1 trading 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

Accepted by SEC EDGAR 08/18/2026 - 06:23 PM EDT

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)
08/14/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	08/14/2026		D		6,977⁽¹⁾	D	$0	61,033	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. Represents shares underlying performance stock awards that were forfeited as a result of below-target performance.

	/s/ Douglas Munro, attorney-in-fact	08/18/2026
	** 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)

Source: View Original Filing on SEC EDGAR