Mersana Therapeutics, Inc.

MRSNDelisted Jan 6, 2026

Industry: Pharmaceutical Preparations
SEC CIK: 0001442836

SEC filings (opens in a new tab)

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.

Q1 2023 vs. Q4 2022

How the institutions holding Mersana Therapeutics, Inc. changed between Q4 2022 and Q1 2023.

All holders in Q1 2023 All holders in Q4 2022

13F holders of MRSN: Q4 2022 compared with Q1 2023
Measure	Q4 2022	Of which not filed for Q1 2023	Q1 2023	Change
Holders	152	1	158	+7
Shares	101.2M	58.6K	106.6M	+5.51M (+5.4%)
Value	$592.8M	$343.0K	$437.2M	−$155.2M (−26.2%)

1 institution that held it in Q4 2022 haven't filed for Q1 2023 yet. Not filing isn't selling, so the changes leave them out.

New holders (26)

Institutions that held Mersana Therapeutics, Inc. at the end of Q1 2023 but not at the end of Q4 2022.

Institutions new to MRSN in Q1 2023
Institution	Shares	Value	% of portfolio
Avidity Partners Management LP	3,433,233	$14.1M	0.47%
Baker Bros. Advisors LP	1,886,115	$7.75M	0.04%
5AM Venture Management, LLC	1,185,000	$4.87M	1.25%
UBS Oconnor LLC	462,699	$1.90M	0.05%
Lion Point Capital, LP	409,120	$1.68M	0.93%
Sectoral Asset Management Inc	343,079	$1.41M	0.27%
Vontobel Holding Ltd.	343,079	$1.41M	0.01%
Caption Management, LLC	295,900	$1.22M	0.26%
Walleye Capital LLC	223,388	$918.1K	0.02%
Tekla Capital Management LLC	162,383	$667.4K	0.03%
Wells Fargo & Company	97,275	$399.8K	0.00%
Profund Advisors LLC	90,095	$370.3K	0.02%
HAP Trading, LLC	89,563	$368.0K	0.09%
CM Wealth Advisors LLC	45,367	$176.0K	0.03%
SEI Investments Co	28,977	$119.1K	0.00%
Bayesian Capital Management, LP	24,800	$101.9K	0.01%
Walleye Trading LLC	21,415	$88.0K	0.00%
Aquatic Capital Management LLC	21,500	$88.0K	0.01%
BIT Capital GmbH	16,931	$69.6K	0.01%
Nebula Research & Development LLC	15,702	$64.5K	0.11%
Lazard Asset Management LLC	10,821	$44.0K	0.00%
Sphera Funds Management Ltd.	10,621	$43.7K	0.01%
Wolverine Trading, LLC	10,259	$41.0K	0.00%
Group One Trading, L.P.	2,099	$8.63K	0.00%
TCI Wealth Advisors, Inc.	986	$4.05K	0.00%
Quadrant Capital Group LLC	116	$477	0.00%

Sold out (19)

Institutions that held Mersana Therapeutics, Inc. at the end of Q4 2022 and filed for Q1 2023 without it.

Institutions that sold out of MRSN in Q1 2023
Institution	Shares, Q4 2022	Value, Q4 2022
Woodline Partners LP	523,408	$3.07M
LMR Partners LLP	500,000	$2.93M
Opaleye Management Inc.	460,000	$2.70M
Fred Alger Management, LLC	378,450	$2.22M
AXA S.A.	104,100	$610.0K
Voloridge Investment Management, LLC	75,216	$440.8K
Jump Financial, LLC	64,613	$378.6K
Harvest Investment Services, LLC	59,563	$349.0K
Oversea-Chinese Banking CORP Ltd	42,500	$249.0K
Ameriprise Financial Inc	27,044	$158.0K
Fox Run Management, L.L.C.	24,652	$144.5K
Boulder Hill Capital Management LP	23,000	$134.8K
Raymond James & Associates	19,431	$113.9K
Two Sigma Securities, LLC	15,226	$89.2K
HRT Financial LP	11,210	$65.0K
Balyasny Asset Management LLC	6,597	$38.7K
Dorsey Wright & Associates	2,988	$17.5K
Lindbrook Capital, LLC	445	$2.61K
Steward Partners Investment Advisory, LLC	225	$1.32K

Not filed for Q1 2023 yet (1)

Institutions that held Mersana Therapeutics, Inc. at the end of Q4 2022 and haven't filed a 13F for Q1 2023. Not filing isn't selling, so they aren't counted as sold out.

Institutions holding MRSN in Q4 2022 that haven't filed for Q1 2023
Institution	Shares, Q4 2022	Value, Q4 2022
Alpha Paradigm Partners, LLC	58,578	$343.0K