Mersana Therapeutics, Inc. - 59045L106
Detailed investor-level table based on 13F positions.
Early Q4 2025 data: only 2 institutional holders reported so far. The full shareholder list will grow as more funds file with the SEC.
Methodology:
Market value and % of portfolio use SEC reported VALUE ($000).
For PUT/CALL positions this reflects reported underlying exposure, not premium cash paid/received.
Details.
Rows: 0
| Investor | History | Status | Shares held | Market value ($000) | % of portfolio | Previous % | Rank | Change in shares | % change in shares | Source | Date reported |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Nextech Invest, Ltd. | History | New | 12,067,246 | 3,571 | 0.68% | — | 1 | +12,067,246 | New | Q2 2025 | Aug 14, 2025 |
| Bain Capital Life Sciences Investors, LLC | History | New | 8,663,673 | 2,564 | 0.32% | — | 2 | +8,663,673 | New | Q2 2025 | Aug 14, 2025 |
| VANGUARD GROUP INC | History | Reduced | 7,678,391 | 2,272 | 0.0% | 0.0% | 3 | -699,376 | -8.35% | Q2 2025 | Aug 11, 2025 |
| AQR CAPITAL MANAGEMENT LLC | History | Reduced | 5,129,685 | 1,518 | 0.0% | 0.0% | 4 | -14,064 | -0.27% | Q2 2025 | Aug 14, 2025 |
| Rock Springs Capital Management LP | History | New | 3,814,684 | 1,129 | 0.07% | — | 5 | +3,814,684 | New | Q2 2025 | Aug 14, 2025 |
| BlackRock, Inc. | History | Reduced | 3,763,419 | 1,113 | 0.0% | 0.0% | 6 | -4,562,763 | -54.8% | Q2 2025 | Aug 12, 2025 |
| SILVERARC CAPITAL MANAGEMENT, LLC | History | New | 3,128,421 | 926 | 0.17% | — | 7 | +3,128,421 | New | Q2 2025 | Aug 14, 2025 |
| ACADIAN ASSET MANAGEMENT LLC | History | New | 2,955,280 | 873 | 0.0% | — | 8 | +2,955,280 | New | Q2 2025 | Aug 07, 2025 |
| RENAISSANCE TECHNOLOGIES LLC | History | Added to | 2,850,194 | 843 | 0.0% | 0.0% | 9 | +2,010,275 | 239.34% | Q2 2025 | Aug 13, 2025 |
| MILLENNIUM MANAGEMENT LLC | History | New | 2,090,235 | 618 | 0.0% | — | 10 | +2,090,235 | New | Q2 2025 | Aug 14, 2025 |
| 683 Capital Management, LLC | History | New | 1,990,000 | 589 | 0.04% | — | 11 | +1,990,000 | New | Q2 2025 | Aug 14, 2025 |
| Catalio Capital Management, LP | History | New | 1,567,413 | 463 | 0.1% | — | 12 | +1,567,413 | New | Q2 2025 | Aug 14, 2025 |
| GOLDMAN SACHS GROUP INC | History | Added to | 1,433,760 | 424 | 0.0% | 0.0% | 13 | +847,102 | 144.39% | Q2 2025 | Aug 14, 2025 |
| JACOBS LEVY EQUITY MANAGEMENT, INC | History | Reduced | 1,332,945 | 394 | 0.0% | 0.0% | 14 | -179 | -0.01% | Q2 2025 | Aug 14, 2025 |
| 5AM Venture Management, LLC | History | New | 1,305,000 | 386 | 0.15% | — | 15 | +1,305,000 | New | Q2 2025 | Aug 14, 2025 |
| GEODE CAPITAL MANAGEMENT, LLC | History | Reduced | 1,049,205 | 310 | 0.0% | 0.0% | 16 | -1,393,123 | -57.04% | Q2 2025 | Aug 08, 2025 |
| LUMINUS MANAGEMENT LLC | History | New | 1,039,314 | 307 | 0.08% | — | 17 | +1,039,314 | New | Q2 2025 | Aug 14, 2025 |
| TWO SIGMA ADVISERS, LP | History | Added to | 937,000 | 277 | 0.0% | 0.0% | 18 | +678,800 | 262.9% | Q2 2025 | Aug 14, 2025 |
| TWO SIGMA INVESTMENTS, LP | History | Added to | 823,269 | 243 | 0.0% | 0.0% | 19 | +769,617 | 1434.46% | Q2 2025 | Aug 14, 2025 |
| UBS Group AG | History | Added to | 775,501 | 229 | 0.0% | 0.0% | 20 | +455,696 | 142.49% | Q2 2025 | Aug 14, 2025 |
| Lion Point Capital, LP | History | New | 644,000 | 190 | 1.29% | — | 21 | +644,000 | New | Q2 2025 | Aug 14, 2025 |
| IEQ CAPITAL, LLC | History | Reduced | 638,452 | 188 | 0.0% | 0.0% | 22 | -68,569 | -9.7% | Q2 2025 | Aug 14, 2025 |
| Alamea Verwaltungs GmbH | History | New | 604,213 | 178 | 0.13% | — | 23 | +604,213 | New | Q2 2025 | Aug 14, 2025 |
| JANE STREET GROUP, LLC | History | New | 511,182 | 151 | 0.0% | — | 24 | +511,182 | New | Q2 2025 | Aug 14, 2025 |
| GSA CAPITAL PARTNERS LLP | History | New | 471,681 | 140 | 0.01% | — | 25 | +471,681 | New | Q2 2025 | Jul 22, 2025 |
| STATE STREET CORP | History | Reduced | 452,110 | 133 | 0.0% | 0.0% | 26 | -2,151,758 | -82.64% | Q2 2025 | Aug 14, 2025 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | History | Added to | 449,369 | 133 | 0.0% | 0.0% | 27 | +208,296 | 86.4% | Q2 2025 | Aug 14, 2025 |
| MORGAN STANLEY | History | Added to | 357,597 | 105 | 0.0% | 0.0% | 28 | +50,467 | 16.43% | Q2 2025 | Aug 14, 2025 |
| Cerity Partners LLC | History | Added to | 320,805 | 94 | 0.0% | 0.0% | 29 | +76,570 | 31.35% | Q2 2025 | Aug 13, 2025 |
| DEUTSCHE BANK AG\ | History | Reduced | 305,070 | 91 | 0.0% | 0.0% | 30 | -534,654 | -63.67% | Q2 2025 | Aug 12, 2025 |
| NORTHERN TRUST CORP | History | Reduced | 222,694 | 65 | 0.0% | 0.0% | 31 | -642,093 | -74.25% | Q2 2025 | Aug 13, 2025 |
| CWM, LLC | History | New | 165,404 | 49 | 0.0% | — | 32 | +165,404 | New | Q2 2025 | Jul 25, 2025 |
| Qube Research & Technologies Ltd | History | Reduced | 152,877 | 45 | 0.0% | 0.0% | 33 | -1,021,720 | -86.98% | Q2 2025 | Aug 14, 2025 |
| FMR LLC | History | Reduced | 138,520 | 41 | 0.0% | 0.0% | 34 | -32,560 | -19.03% | Q2 2025 | Aug 14, 2025 |
| JPMORGAN CHASE & CO | History | Added to | 130,094 | 38 | 0.0% | 0.0% | 35 | +79,390 | 156.58% | Q2 2025 | Aug 12, 2025 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC | History | Reduced | 126,729 | 36 | 0.0% | 0.0% | 36 | -3,971 | -3.04% | Q2 2025 | Jul 10, 2025 |
| ALGERT GLOBAL LLC | History | New | 101,313 | 30 | 0.0% | — | 37 | +101,313 | New | Q2 2025 | Aug 14, 2025 |
| Pallas Capital Advisors LLC | History | New | 96,709 | 28 | 0.0% | — | 38 | +96,709 | New | Q2 2025 | Jul 09, 2025 |
| Jain Global LLC | History | New | 96,154 | 28 | 0.0% | — | 39 | +96,154 | New | Q2 2025 | Aug 14, 2025 |
| HRT FINANCIAL LP | History | New | 93,373 | 27 | 0.0% | — | 40 | +93,373 | New | Q2 2025 | Aug 14, 2025 |
| CITIGROUP INC | History | Reduced | 72,997 | 21 | 0.0% | 0.0% | 41 | -8,628 | -10.57% | Q2 2025 | Aug 11, 2025 |
| Bank of New York Mellon Corp | History | Reduced | 66,577 | 19 | 0.0% | 0.0% | 42 | -279,611 | -80.77% | Q2 2025 | Aug 05, 2025 |
| QVT Financial LP | History | New | 62,657 | 18 | 0.0% | — | 43 | +62,657 | New | Q2 2025 | Aug 14, 2025 |
| Callan Family Office, LLC | History | New | 56,559 | 16 | 0.0% | — | 44 | +56,559 | New | Q2 2025 | Jul 24, 2025 |
| CITADEL ADVISORS LLC | History | Added to | 48,300 | 14 | 0.0% | 0.0% | 45 | +19,000 | 64.85% | Q2 2025 | Aug 14, 2025 |
| R Squared Ltd | History | New | 47,229 | 13 | 0.01% | — | 46 | +47,229 | New | Q2 2025 | Jul 31, 2025 |
| CAPTRUST FINANCIAL ADVISORS | History | Added to | 41,746 | 12 | 0.0% | 0.0% | 47 | +10,612 | 34.08% | Q2 2025 | Aug 15, 2025 |
| GROUP ONE TRADING LLC | History | Added to | 34,856 | 10 | 0.0% | 0.0% | 48 | +14,756 | 73.41% | Q2 2025 | Aug 14, 2025 |
| Vanguard Personalized Indexing Management, LLC | History | Reduced | 36,692 | 10 | 0.0% | 0.0% | 49 | -5,946 | -13.95% | Q2 2025 | Jul 25, 2025 |
| Mariner, LLC | History | Added to | 31,213 | 9 | 0.0% | 0.0% | 50 | +10,463 | 50.42% | Q2 2025 | Aug 14, 2025 |
| Merit Financial Group, LLC | History | Reduced | 31,588 | 9 | 0.0% | 0.0% | 54 | -10,316 | -24.62% | Q2 2025 | Jul 22, 2025 |
| Tower Research Capital LLC (TRC) | History | Added to | 31,684 | 9 | 0.0% | 0.0% | 52 | +5,519 | 21.09% | Q2 2025 | Aug 15, 2025 |
| Focus Partners Wealth | History | Added to | 30,976 | 9 | 0.0% | 0.0% | 53 | +447 | 1.46% | Q2 2025 | Aug 14, 2025 |
| Walleye Trading LLC | History | No change | 31,526 | 9 | 0.0% | 0.0% | 51 | 0 | 0.0% | Q2 2025 | Aug 13, 2025 |
| HSBC HOLDINGS PLC | History | Added to | 30,500 | 8 | 0.0% | 0.0% | 55 | +18,006 | 144.12% | Q2 2025 | Aug 13, 2025 |
| China Universal Asset Management Co., Ltd. | History | New | 25,032 | 7 | 0.0% | — | 56 | +25,032 | New | Q2 2025 | Aug 28, 2025 |
| WELLS FARGO & COMPANY/MN | History | Reduced | 23,014 | 6 | 0.0% | 0.0% | 57 | -55,474 | -70.68% | Q2 2025 | Aug 14, 2025 |
| Jasper Ridge Partners, L.P. | History | No change | 23,100 | 6 | 0.0% | 0.0% | 58 | 0 | 0.0% | Q2 2025 | Aug 14, 2025 |
| BANK OF AMERICA CORP /DE/ | History | Reduced | 20,083 | 5 | 0.0% | 0.0% | 59 | -294,288 | -93.61% | Q2 2025 | Aug 14, 2025 |
| TWO SIGMA SECURITIES, LLC | History | New | 17,566 | 5 | 0.0% | — | 60 | +17,566 | New | Q2 2025 | Aug 14, 2025 |
| PRUDENTIAL FINANCIAL INC | History | Reduced | 14,900 | 4 | 0.0% | 0.0% | 61 | -46,635 | -75.79% | Q2 2025 | Aug 12, 2025 |
| Parcion Private Wealth LLC | History | New | 16,233 | 4 | 0.0% | — | 62 | +16,233 | New | Q2 2025 | Jul 30, 2025 |
| ExodusPoint Capital Management, LP | History | New | 11,434 | 3 | 0.0% | — | 63 | +11,434 | New | Q2 2025 | Aug 13, 2025 |
| Jump Financial, LLC | History | New | 11,323 | 3 | 0.0% | — | 65 | +11,323 | New | Q2 2025 | Aug 13, 2025 |
| Hunter Perkins Capital Management, LLC | History | New | 10,000 | 3 | 0.0% | — | 64 | +10,000 | New | Q2 2025 | Jul 22, 2025 |
| BARCLAYS PLC | History | Reduced | 9,767 | 2 | 0.0% | 0.0% | 66 | -111,958 | -91.98% | Q2 2025 | Feb 27, 2026 |
| EverSource Wealth Advisors, LLC | History | New | 5,494 | 1 | 0.0% | — | 68 | +5,494 | New | Q2 2025 | Aug 13, 2025 |
| Mirae Asset Global Investments Co., Ltd. | History | Added to | 4,814 | 1 | 0.0% | 0.0% | 67 | +680 | 16.45% | Q2 2025 | Jul 21, 2025 |
| Schonfeld Strategic Advisors LLC | History | Closed out | 0 | 0 | — | 0.02% | — | -7,614,064 | -100.0% | Q1 2025 | May 15, 2025 |
| Woodline Partners LP | History | Closed out | 0 | 0 | — | 0.0% | — | -435,593 | -100.0% | Q1 2025 | May 15, 2025 |
| PANAGORA ASSET MANAGEMENT INC | History | Closed out | 0 | 0 | — | 0.0% | — | -370,448 | -100.0% | Q1 2025 | May 15, 2025 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC | History | Closed out | 0 | 0 | — | 0.0% | — | -280,631 | -100.0% | Q1 2025 | Sep 15, 2025 |
| Nuveen, LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -232,223 | -100.0% | Q1 2025 | May 12, 2025 |
| BNP PARIBAS FINANCIAL MARKETS | History | Reduced | 2,765 | 0 | — | 0.0% | — | -198,683 | -98.63% | Q2 2025 | Aug 14, 2025 |
| ALLIANCEBERNSTEIN L.P. | History | Closed out | 0 | 0 | — | 0.0% | — | -186,060 | -100.0% | Q1 2025 | May 15, 2025 |
| RHUMBLINE ADVISERS | History | Closed out | 0 | 0 | — | 0.0% | — | -154,163 | -100.0% | Q1 2025 | May 29, 2025 |
| MACQUARIE GROUP LTD | History | Closed out | 0 | 0 | — | 0.0% | — | -150,000 | -100.0% | Q1 2025 | May 15, 2025 |
| Invesco Ltd. | History | Closed out | 0 | 0 | — | 0.0% | — | -114,863 | -100.0% | Q1 2025 | May 12, 2025 |
| INTECH INVESTMENT MANAGEMENT LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -90,358 | -100.0% | Q1 2025 | May 20, 2025 |
| SEI INVESTMENTS CO | History | Closed out | 0 | 0 | — | 0.0% | — | -69,527 | -100.0% | Q1 2025 | May 14, 2025 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. | History | Closed out | 0 | 0 | — | 0.0% | — | -68,760 | -100.0% | Q1 2025 | May 15, 2025 |
| NEW YORK STATE COMMON RETIREMENT FUND | History | Closed out | 0 | 0 | — | 0.0% | — | -37,235 | -100.0% | Q1 2025 | Oct 08, 2025 |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM | History | Closed out | 0 | 0 | — | 0.0% | — | -28,800 | -100.0% | Q1 2025 | May 12, 2025 |
| MERCER GLOBAL ADVISORS INC /ADV | History | Closed out | 0 | 0 | — | 0.0% | — | -24,077 | -100.0% | Q1 2025 | May 15, 2025 |
| CIBC WORLD MARKETS CORP | History | Closed out | 0 | 0 | — | 0.0% | — | -23,791 | -100.0% | Q1 2025 | May 13, 2025 |
| Police & Firemen's Retirement System of New Jersey | History | Closed out | 0 | 0 | — | 0.0% | — | -22,593 | -100.0% | Q1 2025 | May 09, 2025 |
| Focus Partners Advisor Solutions, LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -19,485 | -100.0% | Q1 2025 | May 15, 2025 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE | History | Closed out | 0 | 0 | — | 0.0% | — | -17,374 | -100.0% | Q1 2025 | May 15, 2025 |
| NorthCrest Asset Manangement, LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -16,069 | -100.0% | Q1 2025 | Apr 16, 2025 |
| GRIMES & COMPANY, INC. | History | Closed out | 0 | 0 | — | 0.0% | — | -14,069 | -100.0% | Q1 2025 | Apr 17, 2025 |
| Legal & General Group Plc | History | Closed out | 0 | 0 | — | 0.0% | — | -11,097 | -100.0% | Q1 2025 | May 15, 2025 |
| PRINCIPAL FINANCIAL GROUP INC | History | Closed out | 0 | 0 | — | 0.0% | — | -10,354 | -100.0% | Q1 2025 | Apr 28, 2025 |
| VICTORY CAPITAL MANAGEMENT INC | History | Closed out | 0 | 0 | — | 0.0% | — | -10,339 | -100.0% | Q1 2025 | May 02, 2025 |
| VOYA INVESTMENT MANAGEMENT LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -10,123 | -100.0% | Q1 2025 | Jun 18, 2025 |
| STRS OHIO | History | Closed out | 0 | 0 | — | 0.0% | — | -8,700 | -100.0% | Q1 2025 | May 28, 2025 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM | History | Closed out | 0 | 0 | — | 0.0% | — | -8,220 | -100.0% | Q1 2025 | May 15, 2025 |
| SIMPLEX TRADING, LLC | History | Closed out | 0 | 0 | — | 0.0% | — | -3,424 | -100.0% | Q1 2025 | May 12, 2025 |
| PNC FINANCIAL SERVICES GROUP, INC. | History | Reduced | 893 | 0 | — | 0.0% | — | -2,644 | -74.75% | Q2 2025 | Aug 08, 2025 |
| ROYAL BANK OF CANADA | History | Reduced | 150 | 0 | — | — | — | -1,468 | -90.73% | Q2 2025 | Nov 21, 2025 |
| SBI Securities Co., Ltd. | History | Closed out | 0 | 0 | — | — | — | -1,368 | -100.0% | Q1 2025 | May 02, 2025 |
| COLDSTREAM CAPITAL MANAGEMENT INC | History | Closed out | 0 | 0 | — | — | — | -1,095 | -100.0% | Q1 2025 | May 13, 2025 |
| Sterling Capital Management LLC | History | Closed out | 0 | 0 | — | — | — | -944 | -100.0% | Q1 2025 | May 13, 2025 |
| OSAIC HOLDINGS, INC. | History | Reduced | 2,598 | 0 | — | 0.0% | — | -736 | -22.08% | Q2 2025 | Sep 04, 2025 |
| IFP Advisors, Inc | History | New | 677 | 0 | — | — | — | +677 | New | Q2 2025 | Jul 24, 2025 |
| NISA INVESTMENT ADVISORS, LLC | History | Reduced | 1,050 | 0 | — | — | — | -250 | -19.23% | Q2 2025 | Jul 31, 2025 |
| North Star Investment Management Corp. | History | New | 150 | 0 | — | — | — | +150 | New | Q2 2025 | Jul 15, 2025 |
| Caitong International Asset Management Co., Ltd | History | New | 1 | 0 | — | — | — | +1 | New | Q2 2025 | Jul 31, 2025 |
| HUNTINGTON NATIONAL BANK | History | No change | 800 | 0 | — | — | — | 0 | 0.0% | Q2 2025 | Aug 05, 2025 |
| Optiver Holding B.V. | History | No change | 2,312 | 0 | — | — | — | 0 | 0.0% | Q2 2025 | Aug 14, 2025 |
| Farther Finance Advisors, LLC | History | No change | 1 | 0 | — | — | — | 0 | 0.0% | Q2 2025 | Jul 11, 2025 |
| GF FUND MANAGEMENT CO. LTD. | History | No change | 2,594 | 0 | — | — | — | 0 | 0.0% | Q2 2025 | Jul 22, 2025 |