Institutional Ownership
Mercury Sys Inc
CUSIP 589378108COMMRCYQ1 2026
13D / 13G Filings
43
Schedule 13D/13G on record
Beneficial Filers
12
Distinct reporting persons
Largest Stake
15.0%
Max % of class reported
Institutional Holders
348
13F filers (latest quarter)
Beneficial Owners — Schedule 13D / 13G
43 filings · latest Mar 4, 2026
| # | Filed | Reporting Person | Form | % of Class | Shares | Filing |
|---|---|---|---|---|---|---|
| 1 | Mar 4, 2026 | Jana Partners Management, LP | 13D/A | 6.9% | — | SEC |
| 2 | Nov 12, 2025 | William Blair Investment Management, LLC | 13G/A | 4.2% | 2.53M | SEC |
| 3 | Nov 10, 2025 | Jana Partners Management, LP | 13D/A | 8.3% | — | SEC |
| 4 | Aug 15, 2025 | Jana Partners Management, LP | 13D/A | 10.0% | — | SEC |
| 5 | Jul 30, 2025 | William Blair Investment Management, LLC | 13G/A | 7.9% | 4.70M | SEC |
| 6 | Jul 17, 2025 | Blackrock, Inc. | 13G/A | 13.3% | 7.97M | SEC |
| 7 | May 13, 2025 | State Street Corporation | 13G | 5.0% | 2.99M | SEC |
| 8 | May 9, 2025 | William Blair Investment Management, LLC | 13G/A | 9.0% | 5.37M | SEC |
| 9 | Feb 12, 2025 | William Blair Investment Management, LLC | 13G/A | 10.8% | 6.43M | SEC |
| 10 | Feb 5, 2025 | State Street Corporation | 13G | 4.9% | 2.94M | SEC |
33 more beneficial-ownership filings on Premium
See the full Schedule 13D/13G history for Mercury Sys Inc.
Unlock full historyTop Institutional Holders (13F)
Largest reported positions · latest quarter
| # | Fund | Shares | Value |
|---|---|---|---|
| 1 | Blackrock, Inc. | 8.92M | $650.38M |
| 2 | Jana Partners Management, LP | 4.11M | $299.47M |
| 3 | State Street Corp | 3.87M | $281.85M |
| 4 | Invesco Ltd. | 2.44M | $178.02M |
| 5 | Conestoga Capital Advisors, LLC | 1.92M | $139.88M |
| 6 | Geode Capital Management, LLC | 1.53M | $111.26M |
| 7 | Dimensional Fund Advisors LP | 1.23M | $89.52M |
| 8 | Goldman Sachs Group Inc | 1.20M | $87.57M |
| 9 | First Trust Advisors LP | 1.16M | $84.63M |
| 10 | Ameriprise Financial Inc | 991.8K | $72.31M |