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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, Q3 2023

Institutional positions in Mersana Therapeutics, Inc. as of Sep 30, 2023. 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

Institutional holders
128
−19 vs. Q2 2023
Shares held
113.7M
+1.24M (+1.1%) vs. Q2 2023
Total value
$144.4M
−$225.8M (−61.0%) vs. Q2 2023
New holders
26
35 more added
Sold out
45
43 more reduced

Compare with Q2 2023: 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.

Institutional holdersQ3 2023: 128 institutions
Q1 2021: 132 institutionsQ2 2021: 131 institutionsQ3 2021: 110 institutionsQ4 2021: 122 institutionsQ1 2022: 128 institutionsQ2 2022: 126 institutionsQ3 2022: 152 institutionsQ4 2022: 152 institutionsQ1 2023: 158 institutionsQ2 2023: 147 institutionsQ3 2023: 128 institutionsQ4 2023: 106 institutionsQ1 2024: 125 institutionsQ2 2024: 122 institutionsQ3 2024: 116 institutionsQ4 2024: 132 institutionsQ1 2025: 111 institutionsQ2 2025: 85 institutionsQ3 2025: 49 institutionsQ4 2025: 51 institutionsQ1 2026: 1 institutionQ2 2026: 0 institutions
Value heldQ3 2023: $144.4M
Q1 2021: $1.14BQ2 2021: $957.8MQ3 2021: $648.3MQ4 2021: $436.6MQ1 2022: $322.7MQ2 2022: $408.0MQ3 2022: $623.4MQ4 2022: $592.8MQ1 2023: $437.2MQ2 2023: $370.2MQ3 2023: $144.4MQ4 2023: $263.0MQ1 2024: $526.3MQ2 2024: $229.6MQ3 2024: $219.4MQ4 2024: $149.2MQ1 2025: $30.2MQ2 2025: $22.9MQ3 2025: $24.7MQ4 2025: $64.8MQ1 2026: $87Q2 2026: $0
Institutions holding MRSN and their total value by quarter
QuarterHoldersValue
Q2 20260$0
Q1 20261$87
Q4 202551$64.8M
Q3 202549$24.7M
Q2 202585$22.9M
Q1 2025111$30.2M
Q4 2024132$149.2M
Q3 2024116$219.4M
Q2 2024122$229.6M
Q1 2024125$526.3M
Q4 2023106$263.0M
Q3 2023128$144.4M
Q2 2023147$370.2M
Q1 2023158$437.2M
Q4 2022152$592.8M
Q3 2022152$623.4M
Q2 2022126$408.0M
Q1 2022128$322.7M
Q4 2021122$436.6M
Q3 2021110$648.3M
Q2 2021131$957.8M
Q1 2021132$1.14B

Institutions, Q3 2023

Shares, value and share of portfolio for each institution holding Mersana Therapeutics, Inc.; share changes are against Q2 2023.

Institutions holding MRSN in Q3 2023
InstitutionSharesValue% of portfolioChange in sharesAction
DAFNA Capital Management LLC734,038$932.2K0.29%−76,807−9.5%Reduced
Decheng Capital Management III (Cayman), LLC904,268$1.15M0.38%00.0%Unchanged
Renaissance Technologies LLC925,919$1.18M0.00%−122,000−11.6%Reduced
Morgan Stanley986,017$1.25M0.00%+221,506+29.0%Added
Northern Trust Corp1,030,586$1.31M0.00%−68,515−6.2%Reduced
Altium Capital Management LP1,059,136$1.35M0.78%+1,059,136New
Baker Bros. Advisors LP1,086,115$1.38M0.01%00.0%Unchanged
Woodline Partners LP1,302,000$1.65M0.02%+1,302,000New
5AM Venture Management, LLC1,305,000$1.66M0.48%00.0%Unchanged
Ikarian Capital, LLC1,579,770$2.01M0.74%+1,529,770+3,059.5%Added
Citadel Advisors LLC1,614,723$2.05M0.00%+1,614,647+2,124,535.5%Added
Boxer Capital, LLC2,000,000$2.54M0.14%+1,000,000+100.0%Added
Walleye Capital LLC2,021,467$2.57M0.04%+1,866,568+1,205.0%Added
Geode Capital Management, LLC2,157,665$2.74M0.00%+151,983+7.6%Added
Millennium Management LLC2,177,650$2.77M0.00%+305,733+16.3%Added
Commodore Capital LP2,244,378$2.85M0.33%+2,244,378New
State Street Corp2,312,742$2.94M0.00%−2,592,407−52.9%Reduced
Philosophy Capital Management LLC2,342,634$2.98M0.62%+2,342,634New
Affinity Asset Advisors, LLC2,850,000$3.62M1.18%+2,850,000New
Rock Springs Capital Management LP3,403,133$4.32M0.12%00.0%Unchanged
Silverarc Capital Management, LLC5,000,000$6.35M2.37%+4,000,000+400.0%Added
Balyasny Asset Management LLC5,040,900$6.40M0.02%+201,385+4.2%Added
Bellevue Group AG5,218,625$6.63M0.11%−8000.0%Reduced
Vanguard Group Inc6,186,123$7.86M0.00%+461,504+8.1%Added
BlackRock Inc.7,972,660$10.1M0.00%+8,678+0.1%Added
Bain Capital Life Sciences Investors, LLC8,663,673$11.0M1.23%00.0%Unchanged
VR Adviser, LLC11,328,000$14.4M1.51%+11,328,000New
EcoR1 Capital, LLC19,364,688$24.6M0.84%+19,364,688New
OrbiMed Advisors LLC0$00.00%−7,214,937−100.0%Sold out
Avoro Capital Advisors LLC0$00.00%−6,375,000−100.0%Sold out
Avidity Partners Management LP0$00.00%−3,790,000−100.0%Sold out
Artal Group S.A.0$00.00%−3,029,555−100.0%Sold out
Deerfield Management Company, L.P. (Series C)0$00.00%−2,885,400−100.0%Sold out
Logos Global Management LP0$00.00%−2,800,000−100.0%Sold out
Candriam Luxembourg S.C.A.0$00.00%−2,415,477−100.0%Sold out
Redmile Group, LLC0$00.00%−1,698,626−100.0%Sold out
Hudson Bay Capital Management LP0$00.00%−962,359−100.0%Sold out
RTW Investments, LP0$00.00%−614,838−100.0%Sold out
Ameriprise Financial Inc0$00.00%−572,273−100.0%Sold out
First Manhattan Co0$00.00%−569,594−100.0%Sold out
Readystate Asset Management LP0$00.00%−567,300−100.0%Sold out
Kennedy Capital Management, Inc.0$00.00%−555,279−100.0%Sold out
Adage Capital Partners GP, L.L.C.0$00.00%−500,000−100.0%Sold out
Tri Locum Partners LP0$00.00%−428,307−100.0%Sold out
Sphera Funds Management Ltd.0$00.00%−418,562−100.0%Sold out
Squarepoint Ops LLC0$00.00%−418,224−100.0%Sold out
Rafferty Asset Management, LLC0$00.00%−336,656−100.0%Sold out
Schonfeld Strategic Advisors LLC0$00.00%−320,540−100.0%Sold out
Algert Global LLC0$00.00%−219,846−100.0%Sold out
Qube Research & Technologies Ltd0$00.00%−204,106−100.0%Sold out
Caption Management, LLC0$00.00%−181,000−100.0%Sold out
Nomura Holdings Inc0$00.00%−148,979−100.0%Sold out
Skandinaviska Enskilda Banken AB (publ)0$00.00%−93,132−100.0%Sold out
Profund Advisors LLC0$00.00%−61,786−100.0%Sold out
Thrivent Financial for Lutherans0$00.00%−58,073−100.0%Sold out
Mirae Asset Global Investments Co., Ltd.0$00.00%−57,099−100.0%Sold out
Jefferies Financial Group Inc.0$00.00%−39,975−100.0%Sold out
Corton Capital Inc.0$00.00%−32,937−100.0%Sold out
State Board of Administration of Florida Retirement System0$00.00%−28,482−100.0%Sold out
Jump Financial, LLC0$00.00%−22,392−100.0%Sold out
E Fund Management Co., Ltd.0$00.00%−18,105−100.0%Sold out
Delphia (USA) Inc.0$00.00%−16,992−100.0%Sold out
Mirabella Financial Services LLP0$00.00%−14,472−100.0%Sold out
Tocqueville Asset Management L.P.0$00.00%−13,000−100.0%Sold out
Dynamic Technology Lab Private Ltd0$00.00%−12,869−100.0%Sold out
Martingale Asset Management L P0$00.00%−12,114−100.0%Sold out
Belvedere Trading LLC0$00.00%−8,081−100.0%Sold out
PEAK6 Investments LLC0$00.00%−5,000−100.0%Sold out
Allspring Global Investments Holdings, LLC0$00.00%−4,681−100.0%Sold out
GWM Advisors LLC0$00.00%−500−100.0%Sold out
Signaturefd, LLC0$00.00%−369−100.0%Sold out
Parallel Advisors, LLC0$00.00%−78−100.0%Sold out
US Bancorp0$00.00%−53−100.0%Sold out