Mercury Systems, Inc. (MRCY) Ownership
MRCY ownership summary
as of October 18, 2026- Institutions
- 112.0% of shares outstanding
- Insiders
- 1.14% of shares outstanding
- Shares outstanding
- 60.9M
- Float
- 55.5M shares available to trade
- Short interest
- 9.53% 5.0M shares short
- Days to cover
- 7.29 short interest down 0.4% vs prior month
- Institutions 111.96%
- Insiders 1.14%
MRCY top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 15.40% | 9.4M | $696.0M | +450,577 (+5.1%) | June 30, 2026 |
| 2 | Jana Partners Management LP | 6.50% | 4.0M | $294.0M | −148,575 (−3.6%) | June 30, 2026 |
| 3 | State Street Corp | 5.62% | 3.4M | $253.9M | −447,429 (−11.6%) | June 30, 2026 |
| 4 | Vanguard Portfolio Management, LLC | 4.98% | 3.0M | $225.1M | +120,555 (+4.1%) | June 30, 2026 |
| 5 | Amvescap Plc. | 4.39% | 2.7M | $198.3M | +227,872 (+9.3%) | June 30, 2026 |
| 6 | Vanguard Capital Management, LLC | 3.98% | 2.4M | $179.9M | +18,811 (+0.8%) | June 30, 2026 |
| 7 | FMR Inc | 3.03% | 1.8M | $136.8M | +938,435 (+103.8%) | June 30, 2026 |
| 8 | T. Rowe Price Investment Management,Inc. | 2.62% | 1.6M | $118.5M | +15,879 (+1.0%) | June 30, 2026 |
| 9 | The Goldman Sachs Group Inc | 2.59% | 1.6M | $117.0M | +374,615 (+31.2%) | June 30, 2026 |
| 10 | Conestoga Capital Advisors, LLC | 2.44% | 1.5M | $110.5M | −431,400 (−22.5%) | June 30, 2026 |
| 11 | Geode Capital Management, LLC | 2.40% | 1.5M | $108.4M | −66,142 (−4.3%) | June 30, 2026 |
| 12 | First Trust Advisors L.P. | 2.13% | 1.3M | $96.5M | +138,182 (+11.9%) | June 30, 2026 |
| 13 | T. Rowe Price Associates, Inc. | 2.11% | 1.3M | $95.5M | +256,960 (+25.0%) | June 30, 2026 |
| 14 | Dimensional Fund Advisors, Inc. | 1.90% | 1.2M | $85.9M | −71,293 (−5.8%) | June 30, 2026 |
| 15 | Segall Bryant & Hamill | 1.69% | 1.0M | $76.5M | +94,667 (+10.1%) | June 30, 2026 |
| 16 | Fisher Asset Management, LLC | 1.55% | 944K | $70.1M | −36,298 (−3.7%) | June 30, 2026 |
| 17 | Franklin Templeton Inc | 1.39% | 847K | $62.9M | +393,099 (+86.7%) | June 30, 2026 |
| 18 | Neuberger Berman Group LLC | 1.38% | 842K | $62.5M | −68,862 (−7.6%) | June 30, 2026 |
| 19 | Morgan Stanley - Brokerage Accounts | 1.33% | 812K | $60.3M | +140,234 (+20.9%) | June 30, 2026 |
| 20 | Wellington Management Company LLP | 1.27% | 776K | $57.6M | +19,977 (+2.6%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 13 holders added 3.2M shares and 7 cut 1.3M.
MRCY top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | iShares Core S&P Small-Cap ETF | 5.46% | 3.3M | $247.0M | +729 (+0.0%) | September 30, 2026 |
| 2 | Vanguard MStar Total Stk Mkt Idx Invest | 2.83% | 1.7M | $127.8M | −2,136 (−0.1%) | August 31, 2026 |
| 3 | First Trust RBA Amer Indl RenaisTM ETF | 2.62% | 1.6M | $118.7M | +922 (+0.1%) | September 30, 2026 |
| 4 | Stt Strt® SPDR® S&P® Arspc & Dfnc ETF | 2.45% | 1.5M | $110.7M | +3,110 (+0.2%) | September 30, 2026 |
| 5 | iShares Russell 2000 ETF | 2.40% | 1.5M | $108.4M | −16,832 (−1.1%) | September 30, 2026 |
| 6 | Invesco Discovery A | 2.11% | 1.3M | $95.3M | +105,947 (+9.0%) | August 31, 2026 |
| 7 | Vanguard Small Cap Index | 2.00% | 1.2M | $90.5M | −24,997 (−2.0%) | September 30, 2026 |
| 8 | VanEck Defense ETF A USD Acc | 1.20% | 733K | $54.4M | +622 (+0.1%) | September 30, 2026 |
| 9 | T. Rowe Price New Horizons | 1.20% | 730K | $54.2M | −15,800 (−2.1%) | September 30, 2026 |
| 10 | American Century Select Inv | 1.15% | 698K | $51.8M | +70,400 (+11.2%) | September 30, 2026 |
| 11 | Vanguard MStar Small Cap Growth Indx Inv | 1.11% | 678K | $50.4M | −35,766 (−5.0%) | September 30, 2026 |
| 12 | Fidelity Small Cap Index | 1.01% | 617K | $45.8M | +7,256 (+1.2%) | July 31, 2026 |
| 13 | Conestoga Small Cap Investors | 0.90% | 549K | $40.8M | −55,715 (−9.2%) | August 31, 2026 |
| 14 | iShares Russell 2000 Growth ETF | 0.87% | 528K | $39.2M | −668 (−0.1%) | September 30, 2026 |
| 15 | iShares US Aerospace & Defense ETF | 0.86% | 526K | $39.1M | −900 (−0.2%) | September 30, 2026 |
| 16 | iShares S&P Small-Cap 600 Growth ETF | 0.85% | 518K | $38.5M | — | September 30, 2026 |
| 17 | State Street SPDR Port S&P 600 Sm CpETF | 0.83% | 508K | $37.7M | — | September 30, 2026 |
| 18 | T. Rowe Price Small-Cap Stock | 0.72% | 440K | $32.7M | −2,531 (−0.6%) | September 30, 2026 |
| 19 | Putnam Small Cap Growth A | 0.72% | 439K | $32.6M | +8,925 (+2.1%) | August 31, 2026 |
| 20 | Fidelity Select Defense & Aerospace | 0.64% | 392K | $29.1M | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
MRCY insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-04-16 | David E Farnsworth | Sell | $84.87 | 3,625 | $307,654 |
| 2026-03-04 | Jana Partners Management, Lp | Sell | $89.68 | 100,899 | $9.0M |
| 2026-03-03 | Jana Partners Management, Lp | Sell | $90.12 | 168,648 | $15.2M |
| 2026-03-02 | Jana Partners Management, Lp | Sell | $94.05 | 182,510 | $17.2M |
| 2026-02-25 | Howard L Lance | Sell | $88.98 | 4,832 | $429,951 |
| 2026-02-17 | Douglas Munro | Sell | $83.56 | 582 | $48,632 |
| 2026-02-17 | Stuart Kupinsky | Sell | $83.56 | 2,287 | $191,102 |
| 2026-02-09 | Jana Partners Management, Lp | Sell | $81.00 | 400,000 | $32.4M |
| 2025-11-12 | Douglas Munro | Sell | $73.42 | 1,329 | $97,575 |
| 2025-11-07 | Debora A Plunkett | Sell | $73.99 | 1,700 | $125,783 |
| 2025-11-06 | Jana Partners Management, Lp | Sell | $75.45 | 1,000,000 | $75.5M |
| 2025-09-16 | Douglas Munro | Sell | $73.40 | 67 | $4,918 |
| 2025-08-20 | Steven Ratner | Sell | $63.76 | 7,000 | $446,320 |
| 2025-08-19 | David E Farnsworth | Sell | $64.46 | 7,572 | $488,091 |
| 2025-08-19 | William L Ballhaus | Sell | $64.46 | 13,050 | $841,203 |
| 2025-08-19 | Stuart Kupinsky | Sell | $64.46 | 1,220 | $78,641 |
| 2025-08-19 | Steven Ratner | Sell | $64.46 | 1,735 | $111,838 |
| 2025-08-19 | Douglas Munro | Sell | $64.46 | 376 | $24,237 |
| 2025-08-18 | David E Farnsworth | Sell | $66.52 | 7,339 | $488,190 |
| 2025-08-18 | Douglas Munro | Sell | $66.52 | 363 | $24,147 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
MRCY shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns MRCY
Institutional investors own 112.0% of Mercury Systems's shares and insiders 1.14%. The largest holder is BlackRock Inc with 15.40% of the shares (9.4M), as of June 30, 2026. Among the top 20 institutions, 13 added shares and 7 reduced their stake in the latest filings. Short interest is 9.53% of the float, or 7.29 days of average trading volume. The share count rose 81.8% since 2014.
Related: MRCY analyst forecast, MRCY key metrics. See the MRCY stock overview for the latest quote and news.
MRCY ownership FAQ
Who owns the most Mercury Systems stock?
The largest shareholders of Mercury Systems are BlackRock Inc (15.40%), Jana Partners Management LP (6.50%), State Street Corp (5.62%), Vanguard Portfolio Management, LLC (4.98%), Amvescap Plc. (4.39%).
What percentage of Mercury Systems is owned by institutions?
Institutions hold 112.0% of Mercury Systems's shares outstanding; insiders hold 1.14%.
Which funds own Mercury Systems?
The largest fund holders of Mercury Systems are iShares Core S&P Small-Cap ETF (5.46%), Vanguard MStar Total Stk Mkt Idx Invest (2.83%), First Trust RBA Amer Indl RenaisTM ETF (2.62%), Stt Strt® SPDR® S&P® Arspc & Dfnc ETF (2.45%), iShares Russell 2000 ETF (2.40%).
What is Mercury Systems's short interest?
5.0M shares of Mercury Systems were sold short, 9.53% of the float; at the average daily volume it would take 7.29 days to cover.
Are insiders buying or selling Mercury Systems?
Of the latest 20 reported insider transactions in Mercury Systems (since August 18, 2025), 0 were purchases and 20 were sales.
How many shares of Mercury Systems are outstanding?
Mercury Systems has 60.9M shares outstanding, of which 55.5M are in the public float.