Mersana Therapeutics, Inc.
MRSNDelisted Jan 6, 2026- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001442836
Mersana Therapeutics, Inc. was delisted on Jan 6, 2026; its insiders filed their last Form 4 on Jan 6, 2026; 51 institutions reported holding it in 13F filings for Q4 2025, worth $64.8M in total; no superinvestor held it.
13F holders, Q4 2025
Institutional positions in Mersana Therapeutics, Inc. as of Dec 31, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works
MRSN is no longer listed, so this page shows Q4 2025. 13F filings for later quarters list far fewer holders.
- Institutional holders
- 51
- +2 vs. Q3 2025
- Shares held
- 2.24M
- −939.5K (−29.5%) vs. Q3 2025
- Total value
- $64.8M
- +$40.1M (+162.4%) vs. Q3 2025
- New holders
- 18
- 3 more added
- Sold out
- 16
- 24 more reduced
Compare with Q3 2025: new holders, sold out and not filed yet
Holders and value by quarter
Institutions reporting MRSN on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.
| Quarter | Holders | Value |
|---|---|---|
| Q2 2026 | 0 | $0 |
| Q1 2026 | 1 | $87 |
| Q4 2025 | 51 | $64.8M |
| Q3 2025 | 49 | $24.7M |
| Q2 2025 | 85 | $22.9M |
| Q1 2025 | 111 | $30.2M |
| Q4 2024 | 132 | $149.2M |
| Q3 2024 | 116 | $219.4M |
| Q2 2024 | 122 | $229.6M |
| Q1 2024 | 125 | $526.3M |
| Q4 2023 | 106 | $263.0M |
| Q3 2023 | 128 | $144.4M |
| Q2 2023 | 147 | $370.2M |
| Q1 2023 | 158 | $437.2M |
| Q4 2022 | 152 | $592.8M |
| Q3 2022 | 152 | $623.4M |
| Q2 2022 | 126 | $408.0M |
| Q1 2022 | 128 | $322.7M |
| Q4 2021 | 122 | $436.6M |
| Q3 2021 | 110 | $648.3M |
| Q2 2021 | 131 | $957.8M |
| Q1 2021 | 132 | $1.14B |
Institutions, Q4 2025
Shares, value and share of portfolio for each institution holding Mersana Therapeutics, Inc.; share changes are against Q3 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Nextech Invest, Ltd. | 482,689 | $14.0M | 1.35% | 00.0% | Unchanged |
| Bain Capital Life Sciences Investors, LLC | 346,545 | $10.0M | 0.77% | 00.0% | Unchanged |
| Vanguard Group Inc | 210,301 | $6.08M | 0.00% | −92,252−30.5% | Reduced |
| Rock Springs Capital Management LP | 152,586 | $4.41M | 0.23% | 00.0% | Unchanged |
| Alamea Verwaltungs GmbH | 24,165 | $3.34M | 2.25% | −405,860−94.4% | Reduced |
| Acadian Asset Management LLC | 110,882 | $3.21M | 0.01% | −31,478−22.1% | Reduced |
| Affinity Asset Advisors, LLC | 100,000 | $2.89M | 0.21% | +100,000 | New |
| BlackRock, Inc. | 69,210 | $2.00M | 0.00% | −26,983−28.1% | Reduced |
| Bank of America Corp | 65,749 | $1.90M | 0.00% | −648−1.0% | Reduced |
| Millennium Management LLC | 63,305 | $1.83M | 0.00% | −14,684−18.8% | Reduced |
| Groupe la Francaise | 61,488 | $1.78M | 0.03% | +61,488 | New |
| Rangeley Capital, LLC | 57,098 | $1.65M | 1.42% | +57,098 | New |
| Gabelli Funds LLC | 47,300 | $1.37M | 0.01% | +47,300 | New |
| Geode Capital Management, LLC | 43,920 | $1.27M | 0.00% | +2,272+5.5% | Added |
| Credit Industriel Et Commercial | 41,392 | $1.20M | 0.17% | +41,392 | New |
| AQR Capital Management LLC | 37,264 | $1.08M | 0.00% | −9,456−20.2% | Reduced |
| Mackenzie Financial Corp | 33,834 | $967.4K | 0.00% | −13,985−29.2% | Reduced |
| Yakira Capital Management, Inc. | 32,663 | $944.9K | 0.32% | +32,663 | New |
| Citadel Advisors LLC | 22,493 | $650.7K | 0.00% | +22,493 | New |
| State Street Corp | 19,543 | $565.4K | 0.00% | −10,300−34.5% | Reduced |
| Morgan Stanley | 18,496 | $535.1K | 0.00% | −29,831−61.7% | Reduced |
| Deltec Asset Management LLC | 18,000 | $520.7K | 0.09% | +18,000 | New |
| Knott David M Jr | 111,686 | $437.8K | 0.20% | +111,686 | New |
| Ieq Capital, LLC | 12,955 | $374.8K | 0.00% | −2,285−15.0% | Reduced |
| XTX Topco Ltd | 11,948 | $345.7K | 0.01% | +11,948 | New |
| Point72 Asset Management, L.P. | 10,364 | $299.8K | 0.00% | +10,364 | New |
| Gamco Investors, Inc. Et Al | 10,000 | $289.3K | 0.00% | +10,000 | New |
| Northern Trust Corp | 8,586 | $248.4K | 0.00% | +8,586 | New |
| Omers Administration Corp | 7,900 | $228.5K | 0.00% | +7,900 | New |
| Equitec Proprietary Markets, LLC | 5,593 | $161.8K | 0.78% | +5,593 | New |
| CWM, LLC | 2,286 | $66.0K | 0.00% | −3,470−60.3% | Reduced |
| BNP Paribas Arbitrage, SA | 1,090 | $31.5K | 0.00% | +559+105.3% | Added |
| Group One Trading, L.P. | 1,073 | $31.0K | 0.00% | +112+11.7% | Added |
| Mint Tower Capital Management B.V. | 1,035 | $30.0K | 0.00% | +1,035 | New |
| Tower Research Capital LLC (TRC) | 376 | $10.9K | 0.00% | −1,186−75.9% | Reduced |
| UBS Group AG | 221 | $6.39K | 0.00% | −8,388−97.4% | Reduced |
| Royal Bank of Canada | 168 | $5.00K | 0.00% | −524−75.7% | Reduced |
| JPMorgan Chase & Co | 112 | $3.24K | 0.00% | −5,996−98.2% | Reduced |
| Advisor Group Holdings, Inc. | 103 | $2.98K | 0.00% | −2,500−96.0% | Reduced |
| Lion Point Capital, LP | 100 | $2.89K | 0.01% | −25,660−99.6% | Reduced |
| Essential Partners LLC | 82 | $2.37K | 0.00% | −34−29.3% | Reduced |
| Flagship Harbor Advisors, LLC | 76 | $2.20K | 0.00% | +76 | New |
| SBI Securities Co., Ltd. | 53 | $1.53K | 0.00% | −1−1.9% | Reduced |
| Wells Fargo & Company | 40 | $1.16K | 0.00% | −1,200−96.8% | Reduced |
| Huntington National Bank | 32 | $926 | 0.00% | 00.0% | Unchanged |
| SHP Wealth Management | 25 | $723 | 0.00% | +25 | New |
| EverSource Wealth Advisors, LLC | 11 | $318 | 0.00% | −3−21.4% | Reduced |
| FMR LLC | 8 | $231 | 0.00% | −4,856−99.8% | Reduced |
| North Star Investment Management Corp. | 6 | $174 | 0.00% | 00.0% | Unchanged |
| IFP Advisors, Inc | 3 | $87 | 0.00% | −612−99.5% | Reduced |
| Danske Bank A/S | 1 | $29 | 0.00% | 00.0% | Unchanged |
| Schonfeld Strategic Advisors LLC | 0 | $0 | 0.00% | −273,579−100.0% | Sold out |
| Silverarc Capital Management, LLC | 0 | $0 | 0.00% | −133,636−100.0% | Sold out |
| 683 Capital Management, LLC | 0 | $0 | 0.00% | −100,000−100.0% | Sold out |
| Renaissance Technologies LLC | 0 | $0 | 0.00% | −88,465−100.0% | Sold out |
| 5AM Venture Management, LLC | 0 | $0 | 0.00% | −52,200−100.0% | Sold out |
| Luminus Management LLC | 0 | $0 | 0.00% | −50,000−100.0% | Sold out |
| Two Sigma Advisers, LP | 0 | $0 | 0.00% | −40,640−100.0% | Sold out |
| Two Sigma Investments, LP | 0 | $0 | 0.00% | −30,688−100.0% | Sold out |
| DRW Securities, LLC | 0 | $0 | 0.00% | −13,851−100.0% | Sold out |
| Voleon Capital Management LP | 0 | $0 | 0.00% | −13,200−100.0% | Sold out |
| China Universal Asset Management Co., Ltd. | 0 | $0 | 0.00% | −875−100.0% | Sold out |
| Barclays PLC | 0 | $0 | 0.00% | −198−100.0% | Sold out |
| Mirae Asset Global Investments Co., Ltd. | 0 | $0 | 0.00% | −193−100.0% | Sold out |
| SRS Capital Advisors, Inc. | 0 | $0 | 0.00% | −157−100.0% | Sold out |
| Citigroup Inc | 0 | $0 | 0.00% | −106−100.0% | Sold out |
| GF Fund Management Co. Ltd. | 0 | $0 | 0.00% | −94−100.0% | Sold out |