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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, Q2 2023

Institutional positions in Mersana Therapeutics, Inc. as of Jun 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
147
−11 vs. Q1 2023
Shares held
112.5M
+5.89M (+5.5%) vs. Q1 2023
Total value
$370.2M
−$67.0M (−15.3%) vs. Q1 2023
New holders
33
56 more added
Sold out
44
41 more reduced

Compare with Q1 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 holdersQ2 2023: 147 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 heldQ2 2023: $370.2M
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, Q2 2023

Shares, value and share of portfolio for each institution holding Mersana Therapeutics, Inc.; share changes are against Q1 2023.

Institutions holding MRSN in Q2 2023
InstitutionSharesValue% of portfolioChange in sharesAction
Bain Capital Life Sciences Investors, LLC8,663,673$28.5M2.94%00.0%Unchanged
BlackRock Inc.7,963,982$26.2M0.00%+490,160+6.6%Added
OrbiMed Advisors LLC7,214,937$23.7M0.46%−1,796,500−19.9%Reduced
Avoro Capital Advisors LLC6,375,000$21.0M0.28%−1,175,000−15.6%Reduced
Vanguard Group Inc5,724,619$18.8M0.00%+1,086,127+23.4%Added
Bellevue Group AG5,219,425$17.2M0.24%+919,806+21.4%Added
State Street Corp4,905,149$16.1M0.00%−1,507,073−23.5%Reduced
Balyasny Asset Management LLC4,839,515$15.9M0.04%+4,839,515New
Avidity Partners Management LP3,790,000$12.5M0.44%+356,767+10.4%Added
Rock Springs Capital Management LP3,403,133$11.2M0.27%−700,670−17.1%Reduced
Artal Group S.A.3,029,555$9.97M0.32%+813,767+36.7%Added
Deerfield Management Company, L.P. (Series C)2,885,400$9.49M0.20%+2,885,400New
Logos Global Management LP2,800,000$9.21M1.27%+2,800,000New
Marshall Wace, LLP2,711,310$8.92M0.02%+214,600+8.6%Added
Sarissa Capital Management LP2,632,900$8.66M0.86%−1,167,100−30.7%Reduced
Candriam Luxembourg S.C.A.2,415,477$7.95M0.06%−547,371−18.5%Reduced
Geode Capital Management, LLC2,005,682$6.60M0.00%+206,835+11.5%Added
Millennium Management LLC1,871,917$6.16M0.01%+610,863+48.4%Added
Redmile Group, LLC1,698,626$5.59M0.21%+1,698,626New
FMR LLC1,479,497$4.87M0.00%+1,355,682+1,094.9%Added
JPMorgan Chase & Co1,443,794$4.75M0.00%+1,322,229+1,087.7%Added
Goldman Sachs Group Inc1,396,018$4.59M0.00%−1,543,522−52.5%Reduced
5AM Venture Management, LLC1,305,000$4.29M1.07%+120,000+10.1%Added
Nuveen Asset Management, LLC1,241,591$4.08M0.00%+1040.0%Added
Deutsche Bank AG1,137,743$3.74M0.00%−9,811−0.9%Reduced
Northern Trust Corp1,099,101$3.62M0.00%+214,468+24.2%Added
Baker Bros. Advisors LP1,086,115$3.57M0.02%−800,000−42.4%Reduced
Renaissance Technologies LLC1,047,919$3.45M0.00%−202,600−16.2%Reduced
Silverarc Capital Management, LLC1,000,000$3.29M1.11%+459,941+85.2%Added
Boxer Capital, LLC1,000,000$3.29M0.15%+1,000,000New
D. E. Shaw & Co., Inc.985,739$3.24M0.01%−820,360−45.4%Reduced
Hudson Bay Capital Management LP962,359$3.17M0.03%+637,359+196.1%Added
Decheng Capital Management III (Cayman), LLC904,268$2.98M0.93%00.0%Unchanged
Charles Schwab Investment Management Inc820,688$2.70M0.00%+91,017+12.5%Added
DAFNA Capital Management LLC810,845$2.67M0.73%+299,982+58.7%Added
Morgan Stanley764,511$2.52M0.00%−1,134,122−59.7%Reduced
RTW Investments, LP614,838$2.02M0.04%+614,838New
Two Sigma Advisers, LP578,100$1.90M0.00%−226,400−28.1%Reduced
Ameriprise Financial Inc572,273$1.88M0.00%+572,273New
First Manhattan Co569,594$1.87M0.01%+569,594New
Readystate Asset Management LP567,300$1.87M0.19%+567,300New
Kennedy Capital Management, Inc.555,279$1.83M0.04%+63,215+12.8%Added
Adage Capital Partners GP, L.L.C.500,000$1.65M0.00%+500,000New
Tri Locum Partners LP428,307$1.41M0.52%+428,307New
Sphera Funds Management Ltd.418,562$1.38M0.30%+407,941+3,840.9%Added
Squarepoint Ops LLC418,224$1.38M0.01%+405,988+3,318.0%Added
Rhenman & Partners Asset Management AB400,000$1.32M0.14%+50,000+14.3%Added
Gsa Capital Partners LLP387,591$1.27M0.13%+183,115+89.6%Added
Bank of New York Mellon Corp376,671$1.24M0.00%+6,885+1.9%Added
Rafferty Asset Management, LLC336,656$1.11M0.01%−149,052−30.7%Reduced
Schonfeld Strategic Advisors LLC320,540$1.05M0.01%+320,540New
Jane Street Group, LLC314,483$1.03M0.00%+314,483New
Bank of America Corp301,493$991.9K0.00%−714,391−70.3%Reduced
Susquehanna International Group, LLP292,317$961.7K0.00%+18,031+6.6%Added
Panagora Asset Management Inc271,501$893.2K0.01%+55,304+25.6%Added
Two Sigma Investments, LP267,270$879.3K0.00%+62,686+30.6%Added
Algert Global LLC219,846$723.3K0.03%+188,500+601.4%Added
Alliancebernstein L.P.216,720$713.0K0.00%+117,020+117.4%Added
Qube Research & Technologies Ltd204,106$671.5K0.00%−47,690−18.9%Reduced
Dimensional Fund Advisors LP189,611$623.7K0.00%−229,726−54.8%Reduced
Barclays PLC186,929$615.0K0.00%−11,104−5.6%Reduced
Cubist Systematic Strategies, LLC186,398$613.2K0.01%−124,543−40.1%Reduced
Caption Management, LLC181,000$595.5K0.10%−114,900−38.8%Reduced
Swiss National Bank178,096$585.9K0.00%+5,800+3.4%Added
UBS Group AG173,617$571.2K0.00%−11,782−6.4%Reduced
Rhumbline Advisers164,871$542.4K0.00%+6,530+4.1%Added
Group One Trading, L.P.160,303$527.4K0.02%+158,204+7,537.1%Added
Walleye Capital LLC154,899$509.6K0.01%−68,489−30.7%Reduced
Macquarie Group Ltd150,000$494.0K0.00%00.0%Unchanged
Nomura Holdings Inc148,979$490.1K0.00%+148,979New
Credit Suisse AG148,463$488.4K0.00%+44,584+42.9%Added
Federated Hermes, Inc.140,645$462.7K0.00%+140,645New
UBS Asset Management Americas Inc102,575$421.6K0.00%00.0%Unchanged
Citigroup Inc125,628$413.3K0.00%−293,644−70.0%Reduced
Price T Rowe Associates Inc119,345$394.0K0.00%−2,032−1.7%Reduced
California State Teachers Retirement System105,346$346.6K0.00%+815+0.8%Added
Wells Fargo & Company102,903$338.6K0.00%+5,628+5.8%Added
Russell Investments Group, Ltd.99,764$328.2K0.00%+81,367+442.3%Added
Skandinaviska Enskilda Banken AB (publ)93,132$306.0K0.00%+34,663+59.3%Added
Alps Advisors Inc84,080$276.6K0.00%+12,909+18.1%Added
BNP Paribas Arbitrage, SA74,002$243.5K0.00%−147,706−66.6%Reduced
Graham Capital Management, L.P.73,744$242.6K0.01%+73,744New
Legal & General Group Plc72,837$239.6K0.00%+36,387+99.8%Added
AQR Capital Management LLC72,043$237.0K0.00%+38,141+112.5%Added
State of Wisconsin Investment Board70,024$230.4K0.00%−3,614−4.9%Reduced
Simplex Trading, LLC65,850$216.0K0.01%+20,308+44.6%Added
QVT Financial LP62,657$206.1K0.01%00.0%Unchanged
Profund Advisors LLC61,786$203.3K0.01%−28,309−31.4%Reduced
Ghost Tree Capital, LLC61,250$201.5K0.07%+61,250New
Thrivent Financial for Lutherans58,073$191.0K0.00%−2,849−4.7%Reduced
Mirae Asset Global Investments Co., Ltd.57,099$186.8K0.00%−6,966−10.9%Reduced
Voya Investment Management LLC56,707$186.6K0.00%−445,452−88.7%Reduced
Ikarian Capital, LLC50,000$164.5K0.06%+50,000New
American International Group, Inc.48,298$158.9K0.00%+3,628+8.1%Added
MetLife Investment Management46,642$153.5K0.00%00.0%Unchanged
Great West Life Assurance Co44,554$147.0K0.00%00.0%Unchanged
Manufacturers Life Insurance Company, The40,866$134.4K0.00%+5,269+14.8%Added
Engineers Gate Manager LP40,740$134.0K0.01%−28,420−41.1%Reduced
Jefferies Financial Group Inc.39,975$131.5K0.00%+39,975New
Invesco Ltd.38,616$127.0K0.00%+5,805+17.7%Added