Comparable stake leader
BlackRock, Inc.
SEC ownership of MERCURY SYSTEMS INC
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001049521.
Disclosed value leader
BlackRock, Inc.
Comparable rows
5/50
Latest evidence
25 Aug 2026
- Public ticker
- MRCY on Nasdaq
- Parsed ownership sources
-
13F, 13D/G, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
BlackRock, Inc.
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
5 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
-
25 Aug 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001049521
- Issuer location
- Andover, MA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
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
5/50
Latest evidence
25 Aug 2026
13F
13D/G
3/4/5
Lead comparable stake: 14%
45 rows are not safely comparable across share classes.
13D/G row: BlackRock, Inc.
Showing 1-8 of 50 holder rows.
Quick read
BlackRock, Inc. leads the comparable SEC ownership view at 14%.
5 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%
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. |
13F
13D/G
Company
|
14%
Reported 13D/G
· 30 Jun 2026
|
$1,146,342,385
9,370,902 shares
|
— | 30 Jun 2026 |
| JANA Partners Management, LP |
13F
13D/G
3/4/5
Company · Director, Other*
|
6.9%
Reported 13D/G
· 03 Mar 2026
|
$484,285,998
3,958,849 shares
|
— | 30 Jun 2026 |
| STATE STREET CORP |
13F
13D/G
Company · STATE STREET CORPORATION
|
6.4%
Reported 13D/G
· 31 Mar 2026
|
$418,046,490
3,418,290 shares
|
— | 30 Jun 2026 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13F
13D/G
Company · Vanguard Portfolio Management
|
5%
Reported 13D/G
· 30 Sep 2026
|
$370,838,380
3,031,459 shares
|
— | 30 Jun 2026 |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC |
13D/G
13F
Company
|
4.2%
Reported 13D/G
· 30 Sep 2025
|
$195,522,694
2,526,133 shares
|
-$167,923,170 | 30 Sep 2025 |
| Invesco Ltd. |
13F
Company
|
—
denominator unverified
|
$326,553,818
2,669,450 shares
|
— | 30 Jun 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
—
denominator unverified
|
$296,360,206
2,422,629 shares
|
— | 30 Jun 2026 |
| FMR LLC |
13F
Company
|
—
denominator unverified
|
$225,344,465
1,842,103 shares
|
— | 30 Jun 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: -$194,029,211.
Buys
$0
Insiders: 0
Sells
$194,029,211
Insiders: 9
Net
-$194,029,211
Shares: -2,335,950
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 2,335,950
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 451,288 | $0 | $41,833,080 | -$41,833,080 |
| 3-6 | 0 | 18,250 | $0 | $1,733,191 | -$1,733,191 |
| 6-9 | 0 | 863,383 | $0 | $74,789,586 | -$74,789,586 |
| 9-12 | 0 | 1,003,029 | $0 | $75,673,354 | -$75,673,354 |
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
-$194.03M
Full value: -$194,029,212 · USD · 12-month changeLatest report
28 Oct 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| JANA Partners Management, LP | Director, Other* | $368,998,942 | -$149,262,246 | -29% | 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 | $33,507,414 | -$37,657,295 | -53% | Mixed | 25 Aug 2026 |
| Mark Aslett | President and CEO, Director | $18,784,325 | Mixed | 21 Feb 2023 | ||
| David E. Farnsworth | Evp, Cfo | $11,707,689 | -$2,737,502 | -19% | Mixed | 19 Aug 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 | ||
| Christopher C. Cambria | EVP, Gen Counsel & Secretary | $5,028,011 | Mixed | 06 Sep 2023 | ||
| Stuart Kupinsky | EVP, CLO & Corp Sec | $4,664,285 | -$842,612 | -15% | Mixed | 21 Oct 2026 |
| Orlando D. Carvalho | Director | $4,548,068 | -$625,527 | -12% | Median | 28 Oct 2026 |
| Charles Roger Wells IV | Evp, Coo | $4,290,000 | Mixed | 15 Feb 2025 | ||
| 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 | ||
| Barry R. Nearhos | Director | $3,118,891 | Median | 28 Oct 2026 | ||
| Michael A. Daniels | Director | $3,002,283 | Mixed | 27 Oct 2021 | ||
| Lisa S. Disbrow | Director | $2,787,472 | Median | 28 Oct 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 | ||
| Howard L. Lance | Director | $2,458,460 | -$1,352,704 | -35% | Median | 28 Oct 2026 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|
| Scott Ostfeld | MRCY | Common Stock, par value $0.01 per share | Award | 2,348 | 0 | 28 Oct 2026 | See footnote | |||
| Gerard J. Demuro | MRCY | Common Stock | Award | 20% | 2,348 | 14,074 | 28 Oct 2026 | Direct | ||
| Debora A. Plunkett | MRCY | Common Stock | Award | 14% | 2,348 | 19,181 | 28 Oct 2026 | Direct | ||
| Barry R. Nearhos | MRCY | Common Stock | Award | 7.4% | 2,348 | 34,077 | 28 Oct 2026 | Direct | ||
| Jean A. Bua | MRCY | Common Stock | Award | 30% | 2,348 | 10,163 | 28 Oct 2026 | Direct | ||
| Howard L. Lance | MRCY | Common Stock | Award | 8.61% | 2,348 | 29,620 | 28 Oct 2026 | Direct | ||
| Lisa S. Disbrow | MRCY | Common Stock | Award | 7.52% | 2,348 | 33,584 | 28 Oct 2026 | Direct | ||
| Orlando D. Carvalho | MRCY | Common Stock | Award | 4.48% | 2,348 | 54,796 | 28 Oct 2026 | Direct | ||
| Stuart Kupinsky | MRCY | Common Stock | Sale | -1.64% | -$76,000 | $76.00 | -1,000 | 59,971 | 21 Oct 2026 | Direct |
| Barry R. Nearhos | MRCY | Common Stock | Award | 0.75% | 235 | 31,729 | 15 Oct 2026 | Direct | ||
| Stuart Kupinsky | MRCY | Common Stock | Sale | -1.61% | -$86,520 | $86.52 | -1,000 | 60,971 | 21 Sep 2026 | Direct |
| Steven Ratner | MRCY | Common Stock | Sale | -17.2% | -$338,030 | $84.51 | -4,000 | 19,275 | 03 Sep 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Sale | -12% | -$4,373,726 | $89.10 | -49,090 | 361,822 | 26 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Options Exercise | 20% | 68,476 | 410,912 | 26 Aug 2026 | Direct | ||
| William L. Ballhaus | MRCY | Employee Stock Option (Right to Buy) | Options Exercise | -100% | -68,476 | 0 | 26 Aug 2026 | Direct | ||
| William L. Ballhaus | MRCY | Common Stock | Sale | -24.5% | -$9,676,615 | $87.12 | -111,076 | 342,436 | 25 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Options Exercise | 51.2% | 153,676 | 453,512 | 25 Aug 2026 | Direct | ||
| William L. Ballhaus | MRCY | Employee Stock Option (Right to Buy) | Options Exercise | -69.2% | -153,676 | 68,476 | 25 Aug 2026 | Direct | ||
| William L. Ballhaus | MRCY | Common Stock | Sale | -26.5% | -$9,684,870 | $89.50 | -108,209 | 299,836 | 24 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Options Exercise | 59.4% | 151,998 | 408,045 | 24 Aug 2026 | Direct | ||
| William L. Ballhaus | MRCY | Employee Stock Option (Right to Buy) | Options Exercise | -100% | -151,998 | 0 | 24 Aug 2026 | Direct | ||
| Steven Ratner | MRCY | Common Stock | Sale | -100% | -$32,524 | $91.36 | -356 | 0 | 21 Aug 2026 | 401K Plan |
| Stuart Kupinsky | MRCY | Common Stock | Sale | -1.74% | -$95,230 | $95.23 | -1,000 | 56,352 | 21 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Sale | -20.2% | -$6,006,485 | $92.41 | -65,000 | 256,047 | 21 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Options Exercise | 40.7% | 92,850 | 321,047 | 21 Aug 2026 | Direct | ||
| William L. Ballhaus | MRCY | Employee Stock Option (Right to Buy) | Options Exercise | -39.8% | -92,850 | 140,650 | 21 Aug 2026 | Direct | ||
| Douglas Munro | MRCY | Common Stock | Sale | -0.83% | -$10,646 | $97.67 | -109 | 12,982 | 20 Aug 2026 | Direct |
| Steven Ratner | MRCY | Common Stock | Sale | -4.22% | -$100,213 | $97.67 | -1,026 | 23,275 | 20 Aug 2026 | Direct |
| David E. Farnsworth | MRCY | Common Stock | Sale | -5.31% | -$645,817 | $97.67 | -6,612 | 117,967 | 20 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Sale | -8.8% | -$2,149,792 | $97.67 | -22,010 | 228,197 | 20 Aug 2026 | Direct |
| Douglas Munro | MRCY | Common Stock | Sale | -4.02% | -$54,968 | $100.31 | -548 | 13,091 | 19 Aug 2026 | Direct |
| Steven Ratner | MRCY | Common Stock | Sale | -8.26% | -$219,369 | $100.31 | -2,187 | 24,301 | 19 Aug 2026 | Direct |
| Stuart Kupinsky | MRCY | Common Stock | Sale | -2.23% | -$131,200 | $100.31 | -1,308 | 57,352 | 19 Aug 2026 | Direct |
| David E. Farnsworth | MRCY | Common Stock | Sale | -6.14% | -$817,995 | $100.31 | -8,155 | 124,579 | 19 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Sale | -9.68% | -$2,688,401 | $100.31 | -26,802 | 250,207 | 19 Aug 2026 | Direct |
| Steven Ratner | MRCY | Common Stock | Sale | -6.93% | -$219,486 | $111.36 | -1,971 | 26,488 | 18 Aug 2026 | Direct |
| Stuart Kupinsky | MRCY | Common Stock | Sale | -1.97% | -$131,179 | $111.36 | -1,178 | 58,660 | 18 Aug 2026 | Direct |
| David E. Farnsworth | MRCY | Common Stock | Sale | -5.24% | -$818,145 | $111.36 | -7,347 | 132,734 | 18 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Sale | -8.02% | -$2,688,620 | $111.36 | -24,144 | 277,009 | 18 Aug 2026 | Direct |
| Steven Ratner | MRCY | Common Stock | Award | 18.2% | 5,187 | 33,646 | 17 Aug 2026 | Direct | ||
| Douglas Munro | MRCY | Common Stock | Award | 20.4% | 2,882 | 17,015 | 17 Aug 2026 | Direct | ||
| Stuart Kupinsky | MRCY | Common Stock | Award | 9.39% | 5,619 | 65,457 | 17 Aug 2026 | Direct | ||
| David E. Farnsworth | MRCY | Common Stock | Award | 5.86% | 8,212 | 148,293 | 17 Aug 2026 | Direct | ||
| William L. Ballhaus | MRCY | Common Stock | Award | 7.85% | 23,629 | 324,782 | 17 Aug 2026 | Direct | ||
| Steven Ratner | MRCY | Common Stock | Sale | -3.67% | -$119,187 | $109.95 | -1,084 | 28,459 | 17 Aug 2026 | Direct |
| Stuart Kupinsky | MRCY | Common Stock | Sale | -1.96% | -$131,391 | $109.95 | -1,195 | 59,838 | 17 Aug 2026 | Direct |
| David E. Farnsworth | MRCY | Common Stock | Sale | -0.95% | -$147,884 | $109.95 | -1,345 | 140,081 | 17 Aug 2026 | Direct |
| William L. Ballhaus | MRCY | Common Stock | Sale | -1.16% | -$388,786 | $109.95 | -3,536 | 301,153 | 17 Aug 2026 | Direct |
| Steven Ratner | MRCY | Common Stock | Disposed to Issuer | -8.36% | -2,695 | 29,543 | 14 Aug 2026 | Direct | ||
| Stuart Kupinsky | MRCY | Common Stock | Disposed to Issuer | -10.3% | -6,977 | 61,033 | 14 Aug 2026 | Direct |
* marks a reported price that did not pass the local price check.