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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, Q4 2023

Institutional positions in Mersana Therapeutics, Inc. as of Dec 31, 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
106
−21 vs. Q3 2023
Shares held
113.3M
+459.0K (+0.4%) vs. Q3 2023
Total value
$263.0M
+$119.7M (+83.6%) vs. Q3 2023
New holders
19
33 more added
Sold out
40
35 more reduced

1 institution that held it in Q3 2023 haven't filed for Q4 2023 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q3 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 holdersQ4 2023: 106 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 heldQ4 2023: $263.0M
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, Q4 2023

Shares, value and share of portfolio for each institution holding Mersana Therapeutics, Inc.; share changes are against Q3 2023.

Institutions holding MRSN in Q4 2023
InstitutionSharesValue% of portfolioChange in sharesAction
EcoR1 Capital, LLC19,364,688$44.9M1.17%00.0%Unchanged
VR Adviser, LLC11,328,000$26.3M1.80%00.0%Unchanged
Balyasny Asset Management LLC9,698,147$22.5M0.06%+4,657,247+92.4%Added
Bain Capital Life Sciences Investors, LLC8,663,673$20.1M1.93%00.0%Unchanged
BlackRock Inc.7,844,282$18.2M0.00%−128,378−1.6%Reduced
Silverarc Capital Management, LLC6,420,136$14.9M4.59%+1,420,136+28.4%Added
Vanguard Group Inc6,237,588$14.5M0.00%+51,465+0.8%Added
Nextech Invest AG5,978,327$13.9M2.58%+5,978,327New
Morgan Stanley4,134,546$9.59M0.00%+3,148,529+319.3%Added
Millennium Management LLC3,394,440$7.88M0.01%+1,216,790+55.9%Added
Rock Springs Capital Management LP3,046,782$7.07M0.17%−356,351−10.5%Reduced
Acuta Capital Partners, LLC2,368,000$5.49M3.09%+2,268,393+2,277.3%Added
State Street Corp2,329,434$5.40M0.00%+16,692+0.7%Added
Geode Capital Management, LLC2,297,136$5.33M0.00%+139,471+6.5%Added
Citadel Advisors LLC1,926,931$4.47M0.00%+312,208+19.3%Added
5AM Venture Management, LLC1,305,000$3.03M0.80%00.0%Unchanged
Philosophy Capital Management LLC1,264,567$2.93M0.59%−1,078,067−46.0%Reduced
Schonfeld Strategic Advisors LLC1,139,407$2.64M0.02%+1,139,407New
Deutsche Bank AG1,139,232$2.64M0.00%+1,076,405+1,713.3%Added
Baker Bros. Advisors LP1,086,115$2.52M0.03%00.0%Unchanged
Affinity Asset Advisors, LLC1,000,000$2.32M0.46%−1,850,000−64.9%Reduced
Northern Trust Corp931,406$2.16M0.00%−99,180−9.6%Reduced
Jacobs Levy Equity Management, Inc930,607$2.16M0.01%+930,607New
Renaissance Technologies LLC865,731$2.01M0.00%−60,188−6.5%Reduced
Atom Investors LP774,659$1.80M0.32%+481,482+164.2%Added
D. E. Shaw & Co., Inc.667,383$1.55M0.00%+599,601+884.6%Added
UBS Oconnor LLC555,645$1.29M0.04%+259,231+87.5%Added
FMR LLC535,628$1.24M0.00%−44,161−7.6%Reduced
Bank of New York Mellon Corp386,659$897.0K0.00%+10,903+2.9%Added
Jane Street Group, LLC371,023$860.8K0.00%+98,018+35.9%Added
Charles Schwab Investment Management Inc308,072$714.7K0.00%+13,667+4.6%Added
Readystate Asset Management LP295,038$684.5K0.04%+295,038New
Panagora Asset Management Inc251,382$583.2K0.00%−411−0.2%Reduced
Bridgeway Capital Management, LLC232,300$538.9K0.01%−349,400−60.1%Reduced
Los Angeles Capital Management LLC197,470$458.1K0.00%00.0%Unchanged
Acadian Asset Management LLC175,808$407.0K0.00%−178,267−50.3%Reduced
Two Sigma Investments, LP171,345$397.5K0.00%+22,279+14.9%Added
Bank of America Corp162,064$376.0K0.00%+44,692+38.1%Added
Rhumbline Advisers160,071$371.4K0.00%−50.0%Reduced
Marshall Wace, LLP157,800$366.1K0.00%00.0%Unchanged
UBS Group AG153,276$355.6K0.00%+96,333+169.2%Added
Susquehanna International Group, LLP152,781$354.5K0.00%−28,071−15.5%Reduced
Barclays PLC152,064$352.8K0.00%+117,910+345.2%Added
Two Sigma Advisers, LP151,400$351.2K0.00%−209,300−58.0%Reduced
Macquarie Group Ltd150,000$348.0K0.00%00.0%Unchanged
Foundations Investment Advisors, LLC102,000$344.8K0.01%+102,000New
Goldman Sachs Group Inc145,565$337.7K0.00%−191,488−56.8%Reduced
Amundi95,540$308.6K0.00%+95,540New
Alliancebernstein L.P.118,180$274.2K0.00%−12,560−9.6%Reduced
Cubist Systematic Strategies, LLC115,656$268.3K0.00%+54,899+90.4%Added
HRT Financial LP105,815$245.0K0.00%+41,636+64.9%Added
Dimensional Fund Advisors LP101,665$235.9K0.00%−10,553−9.4%Reduced
Exchange Traded Concepts, LLC98,729$229.1K0.01%+25,035+34.0%Added
Susquehanna Portfolio Strategies, LLC93,878$217.8K0.00%+93,878New
JPMorgan Chase & Co78,823$182.9K0.00%−188,192−70.5%Reduced
LPL Financial LLC76,694$177.9K0.00%+76,694New
Price T Rowe Associates Inc74,970$174.0K0.00%−12,143−13.9%Reduced
Nuveen Asset Management, LLC65,881$152.8K0.00%00.0%Unchanged
QVT Financial LP62,657$145.4K0.01%00.0%Unchanged
American International Group, Inc.55,108$127.9K0.00%+2,588+4.9%Added
Invesco Ltd.48,730$113.1K0.00%−16,302−25.1%Reduced
Harbor Capital Advisors, Inc.47,472$110.1K0.02%+10,410+28.1%Added
MetLife Investment Management46,642$108.2K0.00%00.0%Unchanged
Voya Investment Management LLC46,033$106.8K0.00%+2,402+5.5%Added
Man Group plc44,600$103.5K0.00%+44,600New
Engineers Gate Manager LP43,694$101.4K0.00%+18,606+74.2%Added
BNP Paribas Arbitrage, SA42,496$98.6K0.00%−80,849−65.5%Reduced
Manufacturers Life Insurance Company, The41,657$96.6K0.00%00.0%Unchanged
Ameriprise Financial Inc41,004$95.1K0.00%+41,004New
SG Americas Securities, LLC39,226$91.0K0.00%−7,414−15.9%Reduced
New York State Common Retirement Fund37,249$86.4K0.00%−107−0.3%Reduced
Royal Bank of Canada34,863$81.0K0.00%+19,933+133.5%Added
Principal Financial Group Inc33,477$77.7K0.00%+1,726+5.4%Added
AQR Capital Management LLC31,559$73.2K0.00%−111,613−78.0%Reduced
Group One Trading, L.P.31,081$72.1K0.00%−10,987−26.1%Reduced
Wells Fargo & Company30,831$71.5K0.00%+7,806+33.9%Added
Legal & General Group Plc29,527$68.5K0.00%−23,635−44.5%Reduced
State Board of Administration of Florida Retirement System28,800$66.8K0.00%+28,800New
Hunter Perkins Capital Management, LLC25,700$60.0K0.01%−11,300−30.5%Reduced
Point72 Middle East FZE25,511$59.2K0.00%+1,167+4.8%Added
Pale Fire Capital SE25,400$58.9K0.01%00.0%Unchanged
Tower Research Capital LLC (TRC)24,533$56.9K0.00%−23,776−49.2%Reduced
Prio Wealth Limited Partnership23,529$54.6K0.00%00.0%Unchanged
Jasper Ridge Partners, L.P.23,100$53.6K0.00%00.0%Unchanged
ProShare Advisors LLC18,350$42.6K0.00%−3,200−14.8%Reduced
California State Teachers Retirement System18,249$42.3K0.00%−80,710−81.6%Reduced
Nisa Investment Advisors, LLC17,643$40.9K0.00%+14,600+479.8%Added
Citigroup Inc15,974$37.1K0.00%+14,239+820.7%Added
Public Employees Retirement System of Ohio15,800$36.7K0.00%+15,800New
Grimes & Company, Inc.15,662$36.3K0.00%−474−2.9%Reduced
Squarepoint Ops LLC13,668$31.7K0.00%+13,668New
Victory Capital Management Inc12,732$29.5K0.00%+12,732New
Bayesian Capital Management, LP11,900$27.6K0.00%+11,900New
Graham Capital Management, L.P.11,811$27.4K0.00%−35,013−74.8%Reduced
Amalgamated Bank11,766$27.0K0.00%−913−7.2%Reduced
Quantbot Technologies LP10,945$25.4K0.00%+10,945New
Ameritas Investment Partners, Inc.9,896$23.0K0.00%00.0%Unchanged
Simplex Trading, LLC5,817$13.0K0.00%−5,453−48.4%Reduced
Advisor Group Holdings, Inc.3,835$8.89K0.00%−92−2.3%Reduced
STRS Ohio2,500$5.00K0.00%00.0%Unchanged