JANA Partners (MRCY) trims Mercury Systems stake with 452,057-share sale

Rhea-AI Filing Summary

MERCURY SYSTEMS INC shareholder JANA Partners Management, LP reported open-market sales of a total of 452,057 shares of Mercury common stock over three days. The sales occurred on March 2, 3, and 4, 2026 at weighted average prices of about $94.05, $90.12, and $89.68 per share, respectively. After these transactions, accounts managed by JANA held 4,114,618 shares of Mercury common stock. JANA states the sales were made to rebalance the holdings of the funds and accounts it manages and disclaims beneficial ownership beyond its pecuniary interest.

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

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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^*

JANA Partners Management, LP

(Last) (First) (Middle)

888 SEVENTH AVENUE

24TH FLOOR

(Street)

NEW YORK NY 10106

(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
	Officer (give title below)	X	Other (specify below)
			See Remarks

3. Date of Earliest Transaction (Month/Day/Year)
03/02/2026

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, par value $0.01 per share ("Common Stock")	03/02/2026		S(1)		182,510	D	$94.05	4,384,165	I	See footnote(2)
Common Stock	03/03/2026		S(1)		168,648	D	$90.12(3)	4,215,517	I	See footnote(2)
Common Stock	03/04/2026		S(1)		100,899	D	$89.68(4)	4,114,618	I	See footnote(2)

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. The transaction reported herein was effected for the purpose of rebalancing the holdings of funds and accounts managed by JANA (as defined below).

2. JANA Partners Management, LP ("JANA" or the "Reporting Person") is a private money management firm which beneficially owns the securities reported herein through various accounts under its management and control. JANA Partners Management GP, LLC (the "GP") is the general partner of JANA. Barry Rosenstein is the Founder of the GP and JANA. JANA, the GP and Barry Rosenstein disclaim any beneficial ownership of any of the Issuer's securities reported herein except to the extent of their pecuniary interest therein, if any.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $89.98 to $90.21, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range set forth herein.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $89.65 to $89.72, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth herein.

Remarks:

The Reporting Person may be deemed to be a director by deputization for purposes of Section 16 under the Securities Exchange Act of 1934 by virtue of the fact that Scott Ostfeld, a Managing Partner and Portfolio Manager of of the Reporting Person, currently serves on the board of directors of the Issuer.

	/s/ JANA Partners Management, LP, by Jennifer Fanjiang, Partner, Chief Legal Officer and Chief Compliance Officer	03/04/2026
	** Signature of Reporting Person	Date
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FAQ

What did JANA Partners report in this Form 4 for MRCY?

JANA Partners reported selling 452,057 shares of Mercury Systems common stock in open-market transactions. The trades took place over three days and were described as rebalancing activity for funds and accounts managed by JANA, rather than a complete exit from the position.

Over what dates did JANA Partners sell Mercury Systems (MRCY) shares?

The reported sales occurred on March 2, 3, and 4, 2026. Each date involved open-market sales of Mercury Systems common stock, with separate weighted average prices disclosed for each trading day in the Form 4 filing submitted by JANA Partners.

How many Mercury Systems (MRCY) shares did JANA Partners sell and at what prices?

JANA sold 452,057 Mercury Systems shares in total. The weighted average prices were $94.05 on March 2, $90.12 on March 3, and $89.68 on March 4, with each day’s sales consisting of multiple trades within narrow price ranges.

How many Mercury Systems (MRCY) shares does JANA Partners hold after these sales?

After the reported transactions, accounts managed by JANA held 4,114,618 shares of Mercury Systems common stock. This post-transaction holding reflects the remaining indirect interest overseen by JANA following the three days of open-market sales disclosed in the Form 4.

Why did JANA Partners say it sold Mercury Systems (MRCY) shares?

JANA stated the transactions were undertaken to rebalance the holdings of funds and accounts it manages. The firm characterized the activity as portfolio rebalancing, rather than providing any broader strategic explanation for reducing its Mercury Systems share position.

Does JANA Partners claim full beneficial ownership of the Mercury Systems (MRCY) shares?

JANA, its general partner, and Barry Rosenstein each disclaim beneficial ownership of Mercury Systems securities beyond any pecuniary interest. The filing notes JANA is a money management firm and holds the reported shares through various managed accounts under its control.