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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
EcoR1 Capital, LLC19,364,688$24.6M0.84%+19,364,688New
VR Adviser, LLC11,328,000$14.4M1.51%+11,328,000New
Bain Capital Life Sciences Investors, LLC8,663,673$11.0M1.23%00.0%Unchanged
BlackRock Inc.7,972,660$10.1M0.00%+8,678+0.1%Added
Vanguard Group Inc6,186,123$7.86M0.00%+461,504+8.1%Added
Bellevue Group AG5,218,625$6.63M0.11%−8000.0%Reduced
Balyasny Asset Management LLC5,040,900$6.40M0.02%+201,385+4.2%Added
Silverarc Capital Management, LLC5,000,000$6.35M2.37%+4,000,000+400.0%Added
Rock Springs Capital Management LP3,403,133$4.32M0.12%00.0%Unchanged
Affinity Asset Advisors, LLC2,850,000$3.62M1.18%+2,850,000New
Philosophy Capital Management LLC2,342,634$2.98M0.62%+2,342,634New
State Street Corp2,312,742$2.94M0.00%−2,592,407−52.9%Reduced
Commodore Capital LP2,244,378$2.85M0.33%+2,244,378New
Millennium Management LLC2,177,650$2.77M0.00%+305,733+16.3%Added
Geode Capital Management, LLC2,157,665$2.74M0.00%+151,983+7.6%Added
Walleye Capital LLC2,021,467$2.57M0.04%+1,866,568+1,205.0%Added
Boxer Capital, LLC2,000,000$2.54M0.14%+1,000,000+100.0%Added
Citadel Advisors LLC1,614,723$2.05M0.00%+1,614,647+2,124,535.5%Added
Ikarian Capital, LLC1,579,770$2.01M0.74%+1,529,770+3,059.5%Added
5AM Venture Management, LLC1,305,000$1.66M0.48%00.0%Unchanged
Woodline Partners LP1,302,000$1.65M0.02%+1,302,000New
Baker Bros. Advisors LP1,086,115$1.38M0.01%00.0%Unchanged
Altium Capital Management LP1,059,136$1.35M0.78%+1,059,136New
Northern Trust Corp1,030,586$1.31M0.00%−68,515−6.2%Reduced
Morgan Stanley986,017$1.25M0.00%+221,506+29.0%Added
Renaissance Technologies LLC925,919$1.18M0.00%−122,000−11.6%Reduced
Decheng Capital Management III (Cayman), LLC904,268$1.15M0.38%00.0%Unchanged
DAFNA Capital Management LLC734,038$932.2K0.29%−76,807−9.5%Reduced
Newtyn Management, LLC700,000$889.0K0.22%+700,000New
Bridgeway Capital Management, LLC581,700$738.8K0.02%+581,700New
FMR LLC579,789$736.3K0.00%−899,708−60.8%Reduced
Sarissa Capital Management LP550,000$698.5K0.09%−2,082,900−79.1%Reduced
Rhenman & Partners Asset Management AB400,000$508.0K0.05%00.0%Unchanged
Bank of New York Mellon Corp375,756$477.2K0.00%−915−0.2%Reduced
Two Sigma Advisers, LP360,700$458.1K0.00%−217,400−37.6%Reduced
Acadian Asset Management LLC354,075$449.0K0.00%+354,075New
Boothbay Fund Management, LLC340,545$432.5K0.02%+330,520+3,297.0%Added
Goldman Sachs Group Inc337,053$428.1K0.00%−1,058,965−75.9%Reduced
UBS Oconnor LLC296,414$376.4K0.01%+296,414New
Charles Schwab Investment Management Inc294,405$373.9K0.00%−526,283−64.1%Reduced
Atom Investors LP293,177$372.3K0.08%+293,177New
Jane Street Group, LLC273,005$346.7K0.00%−41,478−13.2%Reduced
JPMorgan Chase & Co267,015$339.1K0.00%−1,176,779−81.5%Reduced
Panagora Asset Management Inc251,793$319.8K0.00%−19,708−7.3%Reduced
Los Angeles Capital Management LLC197,470$250.8K0.00%+197,470New
Susquehanna International Group, LLP180,852$229.7K0.00%−111,465−38.1%Reduced
Swiss National Bank178,096$226.2K0.00%00.0%Unchanged
Verition Fund Management LLC163,451$207.6K0.00%+163,451New
Rhumbline Advisers160,076$203.3K0.00%−4,795−2.9%Reduced
Marshall Wace, LLP157,800$200.4K0.00%−2,553,510−94.2%Reduced
Macquarie Group Ltd150,000$191.0K0.00%00.0%Unchanged
Two Sigma Investments, LP149,066$189.3K0.00%−118,204−44.2%Reduced
AQR Capital Management LLC143,172$181.8K0.00%+71,129+98.7%Added
Alliancebernstein L.P.130,740$166.0K0.00%−85,980−39.7%Reduced
Credit Suisse AG129,067$163.9K0.00%−19,396−13.1%Reduced
BNP Paribas Arbitrage, SA123,345$156.6K0.00%+49,343+66.7%Added
Walleye Trading LLC121,502$154.3K0.00%+121,502New
Bank of America Corp117,372$149.1K0.00%−184,121−61.1%Reduced
Dimensional Fund Advisors LP112,218$142.5K0.00%−77,393−40.8%Reduced
UBS Asset Management Americas Inc102,575$130.3K0.00%00.0%Unchanged
Gsa Capital Partners LLP101,788$129.0K0.01%−285,803−73.7%Reduced
Acuta Capital Partners, LLC99,607$126.5K0.09%+99,607New
California State Teachers Retirement System98,959$125.7K0.00%−6,387−6.1%Reduced
Alps Advisors Inc88,919$112.9K0.00%+4,839+5.8%Added
Price T Rowe Associates Inc87,113$111.0K0.00%−32,232−27.0%Reduced
XTX Topco Ltd79,215$100.6K0.02%+79,215New
Exchange Traded Concepts, LLC73,694$93.6K0.00%+58,393+381.6%Added
D. E. Shaw & Co., Inc.67,782$86.1K0.00%−917,957−93.1%Reduced
Nuveen Asset Management, LLC65,881$83.7K0.00%−1,175,710−94.7%Reduced
Invesco Ltd.65,032$82.6K0.00%+26,416+68.4%Added
HRT Financial LP64,179$81.0K0.00%+64,179New
Deutsche Bank AG62,827$79.8K0.00%−1,074,916−94.5%Reduced
QVT Financial LP62,657$79.6K0.00%00.0%Unchanged
Ghost Tree Capital, LLC61,250$77.8K0.04%00.0%Unchanged
Cubist Systematic Strategies, LLC60,757$77.2K0.00%−125,641−67.4%Reduced
UBS Group AG56,943$72.3K0.00%−116,674−67.2%Reduced
Legal & General Group Plc53,162$67.5K0.00%−19,675−27.0%Reduced
American International Group, Inc.52,520$66.7K0.00%+4,222+8.7%Added
Tower Research Capital LLC (TRC)48,309$61.4K0.00%+40,906+552.6%Added
Graham Capital Management, L.P.46,824$59.5K0.00%−26,920−36.5%Reduced
MetLife Investment Management46,642$59.2K0.00%00.0%Unchanged
SG Americas Securities, LLC46,640$59.0K0.00%+46,640New
Y-Intercept (Hong Kong) Ltd45,229$57.4K0.01%+33,580+288.3%Added
Great West Life Assurance Co44,554$56.0K0.00%00.0%Unchanged
Voya Investment Management LLC43,631$55.4K0.00%−13,076−23.1%Reduced
Group One Trading, L.P.42,068$53.4K0.00%−118,235−73.8%Reduced
Manufacturers Life Insurance Company, The41,657$52.9K0.00%+791+1.9%Added
New York State Common Retirement Fund37,356$47.4K0.00%+363+1.0%Added
Harbor Capital Advisors, Inc.37,062$47.1K0.01%+15,723+73.7%Added
Hunter Perkins Capital Management, LLC37,000$47.0K0.01%+37,000New
Barclays PLC34,154$43.4K0.00%−152,775−81.7%Reduced
Principal Financial Group Inc31,751$40.3K0.00%+1,412+4.7%Added
Janus Henderson Group PLC30,649$38.8K0.00%+33+0.1%Added
Pale Fire Capital SE25,400$32.3K0.00%00.0%Unchanged
Engineers Gate Manager LP25,088$31.9K0.00%−15,652−38.4%Reduced
Arizona State Retirement System24,427$31.0K0.00%+1,450+6.3%Added
Teacher Retirement System of Texas24,067$31.0K0.00%+1,880+8.5%Added
Point72 Middle East FZE24,344$30.9K0.00%+24,344New
Prio Wealth Limited Partnership23,529$29.9K0.00%00.0%Unchanged
Jasper Ridge Partners, L.P.23,100$29.3K0.00%00.0%Unchanged