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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 2021

Institutional positions in Mersana Therapeutics, Inc. as of Sep 30, 2021. 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
110
−20 vs. Q2 2021
Shares held
68.7M
−108.9K (−0.2%) vs. Q2 2021
Total value
$648.3M
−$286.2M (−30.6%) vs. Q2 2021
New holders
12
45 more added
Sold out
32
34 more reduced

1 institution that held it in Q2 2021 haven't filed for Q3 2021 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q2 2021: 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 2021: 110 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 2021: $648.3M
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 2021

Shares, value and share of portfolio for each institution holding Mersana Therapeutics, Inc.; share changes are against Q2 2021.

Institutions holding MRSN in Q3 2021
InstitutionSharesValue% of portfolioChange in sharesAction
BlackRock Inc.8,807,328$83.1M0.00%−15,376−0.2%Reduced
Avoro Capital Advisors LLC6,800,000$64.1M1.01%00.0%Unchanged
Wellington Management Group LLP6,007,375$56.6M0.01%−869,961−12.6%Reduced
Sarissa Capital Management LP4,299,297$40.5M3.18%+293,697+7.3%Added
Bellevue Group AG4,261,000$40.2M0.41%+1,320,000+44.9%Added
State Street Corp4,090,196$38.6M0.00%+843,673+26.0%Added
Bain Capital Life Sciences Investors, LLC3,695,667$34.9M2.16%00.0%Unchanged
Vanguard Group Inc3,681,594$34.7M0.00%+500,009+15.7%Added
Rock Springs Capital Management LP3,020,702$28.5M0.60%+175,084+6.2%Added
OrbiMed Advisors LLC2,888,847$27.2M0.30%+88,600+3.2%Added
Pictet Asset Management SA2,237,868$21.1M0.02%+2,237,868New
Candriam Luxembourg S.C.A.2,022,895$19.1M0.13%+50,000+2.5%Added
Alkeon Capital Management LLC1,799,838$17.0M0.06%−6,429−0.4%Reduced
Artal Group S.A.1,200,000$11.3M0.28%00.0%Unchanged
Goldman Sachs Group Inc1,145,369$10.8M0.00%+568,414+98.5%Added
Geode Capital Management, LLC1,064,335$10.0M0.00%+12,416+1.2%Added
CIBC Asset Management Inc1,058,798$9.98M0.04%+2920.0%Added
Price T Rowe Associates Inc980,896$9.25M0.00%−1,336,851−57.7%Reduced
Assenagon Asset Management S.A.903,866$8.52M0.04%−137,076−13.2%Reduced
Rho Capital Partners Inc796,458$7.51M4.19%00.0%Unchanged
Northern Trust Corp697,013$6.57M0.00%+14,326+2.1%Added
Morgan Stanley667,889$6.30M0.00%+541,712+429.3%Added
Two Sigma Advisers, LP630,000$5.94M0.02%+62,400+11.0%Added
Charles Schwab Investment Management Inc482,310$4.55M0.00%+69,837+16.9%Added
Marshall Wace, LLP384,736$3.63M0.02%+364,891+1,838.7%Added
Two Sigma Investments, LP348,245$3.28M0.01%−215,785−38.3%Reduced
Nuveen Asset Management, LLC276,188$2.60M0.00%+16,240+6.2%Added
Bank of New York Mellon Corp270,809$2.55M0.00%+21,808+8.8%Added
FMR LLC238,034$2.25M0.00%−141,995−37.4%Reduced
Allianz Asset Management GmbH232,457$2.19M0.00%−50,993−18.0%Reduced
First Manhattan Co218,070$2.06M0.01%+218,070New
Dimensional Fund Advisors LP187,516$1.77M0.00%+11,512+6.5%Added
Hudson Bay Capital Management LP175,000$1.65M0.02%+105,000+150.0%Added
Rafferty Asset Management, LLC162,036$1.53M0.01%+44,558+37.9%Added
Macquarie Group Ltd156,764$1.48M0.00%+5,266+3.5%Added
DAFNA Capital Management LLC140,263$1.32M0.35%+12,000+9.4%Added
Swiss National Bank122,996$1.16M0.00%+2,200+1.8%Added
Walleye Capital LLC119,302$1.13M0.03%+80,487+207.4%Added
Citigroup Inc113,351$1.07M0.00%−72,113−38.9%Reduced
Platinum Investment Management Ltd110,906$1.05M0.03%00.0%Unchanged
Deutsche Bank AG104,207$982.0K0.00%−92,119−46.9%Reduced
Millennium Management LLC103,737$978.0K0.00%−222,406−68.2%Reduced
Voloridge Investment Management, LLC96,451$910.0K0.01%+96,451New
Susquehanna International Group, LLP93,741$884.0K0.00%−16,861−15.2%Reduced
UBS Group AG88,231$832.0K0.00%+64,795+276.5%Added
California State Teachers Retirement System83,710$789.0K0.00%−11,207−11.8%Reduced
Rhumbline Advisers82,743$780.0K0.00%+2,409+3.0%Added
Bank of America Corp77,385$730.0K0.00%+22,153+40.1%Added
Alliancebernstein L.P.72,000$679.0K0.00%00.0%Unchanged
BNP Paribas Arbitrage, SA71,780$676.9K0.00%+69,280+2,771.2%Added
State of Wisconsin Investment Board71,600$675.0K0.00%−8,100−10.2%Reduced
AlphaCentric Advisors LLC65,500$618.0K0.16%+20,000+44.0%Added
QVT Financial LP62,657$591.0K0.05%00.0%Unchanged
Marshall Wace North America L.P.59,082$558.0K0.00%+59,082New
Credit Suisse AG52,096$492.0K0.00%−2,061−3.8%Reduced
New York State Common Retirement Fund51,864$489.0K0.00%−7,581−12.8%Reduced
D. E. Shaw & Co., Inc.48,605$458.0K0.00%+8,520+21.3%Added
Teachers Retirement System of the State of Kentucky47,980$452.0K0.00%+11,141+30.2%Added
Citadel Advisors LLC46,843$442.0K0.00%−542,280−92.0%Reduced
Jane Street Group, LLC45,632$430.0K0.00%−6,740−12.9%Reduced
TD Asset Management Inc45,057$425.0K0.00%−28,897−39.1%Reduced
UBS Asset Management Americas Inc43,419$409.4K0.00%00.0%Unchanged
American International Group, Inc.39,172$369.0K0.00%+584+1.5%Added
Manufacturers Life Insurance Company, The38,053$359.0K0.00%−1,753−4.4%Reduced
SG Americas Securities, LLC36,713$346.0K0.00%+36,713New
Parametric Portfolio Associates LLC33,572$317.0K0.00%−2,414−6.7%Reduced
Barclays PLC33,016$312.0K0.00%−24,349−42.4%Reduced
Invesco Ltd.32,211$303.0K0.00%+5,166+19.1%Added
JPMorgan Chase & Co31,518$297.0K0.00%+1,658+5.6%Added
PDT Partners, LLC30,495$288.0K0.02%+30,495New
State Board of Administration of Florida Retirement System27,117$256.0K0.00%00.0%Unchanged
Voya Investment Management LLC26,438$249.0K0.00%00.0%Unchanged
Principal Financial Group Inc26,013$245.0K0.00%−27−0.1%Reduced
Legal & General Group Plc25,114$236.0K0.00%+11,108+79.3%Added
ProShare Advisors LLC24,499$231.0K0.00%−5,867−19.3%Reduced
Walleye Trading LLC23,650$223.0K0.01%+8,450+55.6%Added
Prio Wealth Limited Partnership23,529$222.0K0.01%00.0%Unchanged
Jasper Ridge Partners, L.P.23,100$218.0K0.01%00.0%Unchanged
Boothbay Fund Management, LLC22,764$215.0K0.01%+6,693+41.6%Added
DekaBank Deutsche Girozentrale21,000$195.0K0.00%00.0%Unchanged
Virtu Financial LLC18,777$177.0K0.02%+18,777New
Algert Global LLC17,892$169.0K0.02%+17,892New
MetLife Investment Management17,368$163.8K0.00%−8,457−32.7%Reduced
Truist Financial Corp16,700$157.0K0.00%00.0%Unchanged
Arizona State Retirement System15,158$143.0K0.00%+262+1.8%Added
Metropolitan Life Insurance Co14,952$141.0K0.00%−4,820−24.4%Reduced
Virtus ETF Advisers LLC14,165$134.0K0.06%−747−5.0%Reduced
Allstate Corp13,667$129.0K0.01%−329−2.4%Reduced
AQR Capital Management LLC12,330$116.0K0.00%00.0%Unchanged
Amalgamated Bank11,850$112.0K0.00%−171−1.4%Reduced
Fox Run Management, L.L.C.11,779$111.0K0.07%+11,779New
Zurcher Kantonalbank (Zurich Cantonalbank)10,092$95.0K0.00%+11+0.1%Added
Tower Research Capital LLC (TRC)8,693$82.0K0.00%+2,868+49.2%Added
Royal Bank of Canada6,941$66.0K0.00%+2,226+47.2%Added
First Mercantile Trust Co5,541$52.0K0.01%−225−3.9%Reduced
Ameritas Investment Partners, Inc.5,400$51.0K0.00%00.0%Unchanged
Wells Fargo & Company5,360$50.0K0.00%+5,308+10,207.7%Added
Group One Trading, L.P.3,849$36.0K0.00%+3,849New
Great West Life Assurance Co3,638$34.0K0.00%00.0%Unchanged
Penserra Capital Management LLC1,640$15.0K0.00%+55+3.5%Added