SEC ownership of MERCURY SYSTEMS INC

Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001049521.

Comparable stake leader

BlackRock, Inc.

Disclosed value leader

BlackRock, Inc.

Comparable rows

50/50

Latest evidence

16 Jul 2026

Ownership snapshot CIK-linked ownership evidence from parsed SEC filings. 3 signals
Comparable ownership rows
50 of 50
Meaning: Rows with safely comparable ownership %
Latest 13D/G holder
BlackRock, Inc.
Source: Latest parsed Schedule 13D/G stake
Latest parsed ownership date
16 Jul 2026
Freshness: Most recent filing date in this holder set
Issuer Names, identifiers, and filing context for this profile. 2 identity fields
Issuer CIK
0001049521
Issuer location
Andover, MA

Ownership snapshot

Top shareholders of MERCURY SYSTEMS INC (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Comparable stake leader
BlackRock, Inc.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
16 Jul 2026
13D/G 13F 3/4/5 Lead comparable stake: 14% 13D/G row: BlackRock, Inc. Showing 1-8 of 50 holder rows.

Quick read

BlackRock, Inc. leads the comparable SEC ownership view at 14%.

50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.

Open SEC evidence Opens BlackRock, Inc.'s linked filing trail.
Comparable ownership Top 5
BlackRock, Inc. 14%
JANA Partners Management, LP 6.9%
STATE STREET CORP 6.4%
VANGUARD PORTFOLIO MANAGEMENT LLC 5.1%
WILLIAM BLAIR INVESTMENT MANAGEME... 4.2%

Ownership % is shown only when SEC disclosures are safely comparable across share classes.

Detailed SEC evidence table Showing 1-8 of 50 holder rows
Holder Evidence Ownership % Position 12M Net Δ As of
BlackRock, Inc.
13D/G 13F
Company
14%
$1,054,426,738
8,619,527 shares
+$79,181,028 30 Jun 2026
JANA Partners Management, LP
3/4/5 13D/G 13F
Director, Other* · Company
6.9%
from 13D/G
$368,998,942
4,114,618 shares
-$201,401,986 02 Mar 2026
STATE STREET CORP
13D/G 13F
STATE STREET CORPORATION · Company
6.4%
$307,711,232
3,865,719 shares
+$69,931,306 31 Mar 2026
VANGUARD PORTFOLIO MANAGEMENT LLC
13D/G 13F
Vanguard Portfolio Management · Company
5.1%
$333,241,613
3,086,142 shares
$0 30 Jun 2026
WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC
13D/G 13F
Company
4.2%
$195,522,694
2,526,133 shares
-$167,923,170 30 Sep 2025
William L. Ballhaus
3/4/5
Chairman, President & CEO, Director
0.64%
$24,608,248
383,198 shares
-$1,532,692 18 Aug 2025
David E. Farnsworth
3/4/5
EVP, CFO
0.26%
$13,487,842
159,120 shares
-$1,283,945 16 Apr 2026
Stuart Kupinsky
3/4/5
EVP, CLO & Corp Sec
0.11%
$5,791,927
69,092 shares
-$348,360 17 Feb 2026
How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

Forms 3/4/5 flow

Insider trading overview

Net insider flow leans to selling over the last 12 months. Net value: -$207,725,389.

Buys
$0
Insiders: 0
Sells
$207,725,389
Insiders: 9
Net
-$207,725,389
Shares: -2,733,642
Window
Last 12 months
4 rolling buckets
Buy value Sell value
Shares: 0 Shares: 2,733,642
Window (months) Buy shares Sell shares Buy value Sell value Net value
0-3 0 18,250 $0 $1,733,191 -$1,733,191
3-6 0 863,383 $0 $74,789,586 -$74,789,586
6-9 0 1,003,029 $0 $75,673,354 -$75,673,354
9-12 0 848,980 $0 $55,529,258 -$55,529,258

Reporting owners

Insider holders from Forms 3/4/5

Showing 1-20 of 32 reporting-owner rows connected to MERCURY SYSTEMS INC. Open a relationship link for the CIK-to-CIK filing trail.

Rows
32
Largest Forms 3/4/5 holder
JANA Partners Management, LP
Net 12M change
-$207,725,390
Latest report
16 Jul 2026
Name Relationship Holdings Value Past Year Net Change Change % Valuation Report Date
JANA Partners Management, LP Director, Other* $368,998,942 -$201,401,986 -35% Filing P/S 02 Mar 2026
JANA PARTNERS LLC Director, Other* $173,843,076 Mixed 18 Aug 2023
William L. Ballhaus Chairman, President & CEO, Director $24,608,248 -$1,532,692 -5.9% Mixed 18 Aug 2025
Mark Aslett President and CEO, Director $18,784,325 Mixed 21 Feb 2023
David E. Farnsworth Evp, Cfo $13,487,842 -$1,283,945 -8.7% Mixed 16 Apr 2026
Didier M. C. Thibaud Evp, Coo $9,073,968 Mixed 16 Aug 2021
Michael Ruppert EVP, CFO and Treasurer $7,479,843 Mixed 16 Feb 2023
Stuart Kupinsky EVP, CLO & Corp Sec $5,791,927 -$348,360 -5.7% Mixed 17 Feb 2026
Christopher C. Cambria EVP, Gen Counsel & Secretary $5,028,011 Mixed 06 Sep 2023
Orlando D. Carvalho Director $4,686,805 -$625,527 -12% Filing P/S 12 May 2026
Charles Roger Wells IV Evp, Coo $4,290,000 Mixed 15 Feb 2025
Barry R. Nearhos Director $4,280,816 Median 16 Jul 2026
Brian E. Perry EVP, President Processing $3,246,810 Mixed 18 Aug 2022
James M. Stevison EVP, President Mission Systems $3,207,439 Mixed 16 Oct 2023
Michael A. Daniels Director $3,002,283 Mixed 27 Oct 2021
Steven Ratner Evp, Chro $3,001,650 -$854,891 -22% Mixed 11 May 2026
Bass James K. Director $2,495,593 Mixed 27 Oct 2021
William K. Obrien Director $2,475,557 Mixed 26 Oct 2022
Thomas Huber EVP Chief Transformation Offic $2,459,137 Mixed 21 Feb 2023
Allen Couture EVP, Execution Excellence $2,425,338 Mixed 18 Oct 2023

Recent insider transactions for MERCURY SYSTEMS INC

Showing up to 300 recent insider transactions from the last 12 months.

Insider Symbol Class Transaction % SEC-reported value SEC-reported price Shares Shares owned Date Ownership
Barry R. Nearhos MRCY Common Stock Award 0.54% 170 31,494 16 Jul 2026 Direct
Howard L. Lance MRCY Common Stock Sale -100% $922,744 $99.76 -9,250 0 26 May 2026 By The Howard L. Lance Revocable Living Trust Dated 9/1/2006
Orlando D. Carvalho MRCY Common Stock Sale -11.8% $625,527 $89.36 -7,000 52,448 12 May 2026 Direct
Steven Ratner MRCY Common Stock Sale -5.84% $184,920 $92.46 -2,000 32,238 11 May 2026 Direct
Barry R. Nearhos MRCY Common Stock Award 0.79% 245 31,324 16 Apr 2026 Direct
David E. Farnsworth MRCY Common Stock Sale -2.25% $307,661 $84.87 -3,625 157,701 16 Apr 2026 Direct
Steven Ratner MRCY Common Stock Award 1.29% 437 34,238 16 Mar 2026 Direct
JANA Partners Management, LP MRCY Common Stock Sale -2.39% $9,048,622 $89.68 -100,899 4,114,618 04 Mar 2026 See footnote
JANA Partners Management, LP MRCY Common Stock Sale -3.85% $15,198,558 $90.12 -168,648 4,215,517 03 Mar 2026 See footnote
JANA Partners Management, LP MRCY Common Stock, par value $0.01 per share ("Common Stock") Sale -4% $17,165,066 $94.05 -182,510 4,384,165 02 Mar 2026 See footnote
Howard L. Lance MRCY Common Stock Sale -15% $429,960 $88.98 -4,832 27,272 25 Feb 2026 Direct
Stuart Kupinsky MRCY Common Stock Sale -3.25% $191,091 $83.56 -2,287 68,010 17 Feb 2026 Direct
Douglas Munro MRCY Common Stock Sale -3.9% $48,629 $83.56 -582 14,328 17 Feb 2026 Direct
JANA Partners Management, LP MRCY Common Stock, par value $0.01 per share Sale -8.05% $32,400,000 $81.00 -400,000 4,566,675 09 Feb 2026 See footnote
Barry R. Nearhos MRCY Common Stock Award 1.55% 474 31,079 15 Jan 2026 Direct
Douglas Munro MRCY Common Stock Sale -8.3% $97,570 $73.42 -1,329 14,678 12 Nov 2025 Direct
Debora A. Plunkett MRCY Common Stock Sale -9.17% $125,784 $73.99 -1,700 16,833 07 Nov 2025 Direct
JANA Partners Management, LP MRCY Common Stock, par value $0.01 per share Sale -16.8% $75,450,000 $75.45 -1,000,000 4,966,675 06 Nov 2025 See footnote
Jean A. Bua MRCY Common Stock Award 43.3% 2,362 7,815 22 Oct 2025 Direct
JANA Partners Management, LP MRCY Common Stock, par value $0.01 per share Award 0.04% 2,362 5,966,675 22 Oct 2025 See footnotes
Debora A. Plunkett MRCY Common Stock Award 14.6% 2,362 18,533 22 Oct 2025 Direct
Gerard J. Demuro MRCY Common Stock Award 15.6% 2,362 17,481 22 Oct 2025 Direct
Barry R. Nearhos MRCY Common Stock Award 8.36% 2,362 30,605 22 Oct 2025 Direct
Howard L. Lance MRCY Common Stock Award 7.94% 2,362 32,104 22 Oct 2025 Direct
Orlando D. Carvalho MRCY Common Stock Award 4.14% 2,362 59,448 22 Oct 2025 Direct
Lisa S. Disbrow MRCY Common Stock Award 8.18% 2,362 31,236 22 Oct 2025 Direct
Barry R. Nearhos MRCY Common Stock Award 1.75% 487 28,243 16 Oct 2025 Direct
Douglas Munro MRCY Common Stock Sale -0.42% $4,918 $73.40 -67 16,007 16 Sep 2025 Direct
Steven Ratner MRCY Common Stock Sale -17.2% $446,312 $63.76 -7,000 33,801 20 Aug 2025 Direct
Douglas Munro MRCY Common Stock Sale -2.29% $24,238 $64.46 -376 16,074 19 Aug 2025 Direct
Steven Ratner MRCY Common Stock Sale -4.08% $111,845 $64.46 -1,735 40,801 19 Aug 2025 Direct
Stuart Kupinsky MRCY Common Stock Sale -1.71% $78,646 $64.46 -1,220 70,297 19 Aug 2025 Direct
David E. Farnsworth MRCY Common Stock Sale -4.48% $488,121 $64.46 -7,572 161,326 19 Aug 2025 Direct
William L. Ballhaus MRCY Common Stock Sale -3.36% $841,255 $64.46 -13,050 374,976 19 Aug 2025 Direct
Douglas Munro MRCY Common Stock Sale -2.16% $24,145 $66.52 -363 16,450 18 Aug 2025 Direct
Steven Ratner MRCY Common Stock Sale -3.8% $111,814 $66.52 -1,681 42,536 18 Aug 2025 Direct
Stuart Kupinsky MRCY Common Stock Sale -1.63% $78,622 $66.52 -1,182 71,517 18 Aug 2025 Direct
David E. Farnsworth MRCY Common Stock Sale -4.16% $488,163 $66.52 -7,339 168,898 18 Aug 2025 Direct
William L. Ballhaus MRCY Common Stock Sale -2.61% $691,437 $66.52 -10,395 388,026 18 Aug 2025 Direct
Douglas Munro MRCY Common Stock Award 25.2% 3,380 16,813 15 Aug 2025 Direct
Steven Ratner MRCY Common Stock Award 25.7% 9,043 44,217 15 Aug 2025 Direct
Stuart Kupinsky MRCY Common Stock Award 15.7% 9,865 72,699 15 Aug 2025 Direct
David E. Farnsworth MRCY Common Stock Award 8.07% 13,153 176,237 15 Aug 2025 Direct
William L. Ballhaus MRCY Common Stock Award 12.7% 44,940 398,421 15 Aug 2025 Direct
JANA Partners Management, LP MRCY Common Stock, par value $0.01 per share Sale -11.8% $52,139,740 $65.42 -797,000 5,964,313 13 Aug 2025 See footnote
* marks a reported price that did not pass the local price check.
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