Mersana Therapeutics, Inc.

MRSN • NASDAQ

Mersana Therapeutics, Inc. is a biotechnology company in the healthcare sector on NASDAQ, led by Martin Huber, M.D., with a market cap of $141.7M. As of Q3 2025, 64% of shares are held by 45 institutional investors, with Nextech Invest, Ltd. as the largest holder at 9.67%.

President and Chief Executive OfficerMartin Huber, M.D.

Market Cap$141.7M

Biotechnology

Healthcare

Employees123.0

Websitemersana.com

Country

United States of America

Overview

Overview of institutional ownership in MRSN as of Q3 2025 with a market cap of $38.7M

All Institutions

Institutions: 45
Value Held: $24.7M
Shares Held: 3.2M
Avg Position: $548.5K
Median Position: $199.9K

Hedge Funds

Hedge Funds: 12
Value Held: $8.0M
Shares Held: 1.0M
Avg Position: $668.2K
Median Position: $496.6K

Ownership Breakdown

Institutional (non-HF)

43.04%

$16.7M

Hedge Funds

20.7%

$8.0M

Retail & Other

36.26%

$14.0M

Based on market cap of $38.7M as of Q3 2025. Institutional (non-HF) excludes hedge funds to avoid double counting.

Biggest Investors

Institutions with the largest positions in MRSN as of Q3 2025

Institution	Key People	Position Value	Ownership	Owned Since	Total AUM (Long)
N Nextech Invest, Ltd. Institution	-	$3.7M 0.57% of portfolio	9.67% 482.7K shares	Q1 2025 Held for 8 months	$657.0M
A Alamea Verwaltungs GmbH Institution	-	$3.3M 2.28% of portfolio	8.62% 430.0K shares	Q1 2025 Held for 8 months	$146.4M
B Bain Capital Life Sciences Investors, LLC Institution	-	$2.7M 0.18% of portfolio	6.94% 346.5K shares	Q2 2020 Held for 5y 5m	$1.5B
VANGUARD GROUP INC Institution	Salim Ramji CEO	$2.3M 0.00% of portfolio	6.06% 302.6K shares	Q2 2017 Held for 8y 5m	$6.69T
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	Ryan Andrew Tolkin CEO	$2.1M 0.01% of portfolio	5.48% 273.6K shares	Q2 2023 Held for 2y 5m	$14.3B
Rock Springs Capital Management LP Hedge Fund•Sector	Nnamdi C Etoh CFO	$1.2M 0.07% of portfolio	3.06% 152.6K shares	Q2 2017 Held for 8y 5m	$1.7B
ACADIAN ASSET MANAGEMENT LLC Long Only Manager	Gillian Morna Therese Savage CEO	$1.1M 0.00% of portfolio	2.85% 142.4K shares	Q3 2023 Held for 2y 2m	$51.5B
SILVERARC CAPITAL MANAGEMENT, LLC Hedge Fund•Long/Short	Devesh Sharad Gandhi Founder	$1.0M 0.15% of portfolio	2.68% 133.6K shares	Q2 2022 Held for 3y 5m	$689.7M
6 683 Capital Management, LLC Hedge Fund•Long/Short	Ari Jonathan Zweiman Managing Partner	$776.0K 0.07% of portfolio	2.00% 100.0K shares	Q3 2024 Held for 1y 2m	$1.1B
B BlackRock, Inc. Institution	-	$746.5K 0.00% of portfolio	1.93% 96.2K shares	Q3 2017 Held for 8y 2m	$5.67T

Net Capital Flow

Institutional buying and selling activity for MRSN in Q3 2025

Traded: +$863.3K
Buyers: 23
Sellers: 57
Total Bought: +$5.5M
Total Sold: −$4.6M
Avg Position: $287.0K

Biggest Buyers

Institution	Net Bought	Current Position
A Alamea Verwaltungs GmbH Institution	+$3.1M +405.9K shares	$3.3M 430.0K shares
BANK OF AMERICA CORP /DE/ Institution	+$509.0K +65.6K shares	$515.2K 66.4K shares
MACKENZIE FINANCIAL CORP Long Only Manager	+$371.1K +47.8K shares	$371.1K 47.8K shares
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	+$361.8K +46.6K shares	$2.1M 273.6K shares
MORGAN STANLEY RIA/Wealth	+$264.0K +34.0K shares	$375.0K 48.3K shares
ACADIAN ASSET MANAGEMENT LLC Long Only Manager	+$187.4K +24.1K shares	$1.1M 142.4K shares
6 683 Capital Management, LLC Hedge Fund•Long/Short	+$158.3K +20.4K shares	$776.0K 100.0K shares
D DRW Securities, LLC Institution	+$107.5K +13.9K shares	$107.5K 13.9K shares
Voleon Capital Management LP Hedge Fund•Quant	+$102.4K +13.2K shares	$102.4K 13.2K shares
STATE STREET CORP Institution	+$91.2K +11.8K shares	$231.6K 29.8K shares

Biggest Sellers

Institution	Net Sold	Current Position
AQR CAPITAL MANAGEMENT LLC Hedge Fund•Multi-Strategy	−$1.2M −158.5K shares	$362.5K 46.7K shares
Catalio Capital Management, LP Venture Capital	−$464.0K −62.7K shares	Sold Off 0 shares
GOLDMAN SACHS GROUP INC Institution	−$424.4K −57.4K shares	Sold Off 0 shares
B BlackRock, Inc. Institution	−$421.7K −54.3K shares	$746.5K 96.2K shares
JACOBS LEVY EQUITY MANAGEMENT, INC Hedge Fund•Quant	−$394.6K −53.3K shares	Sold Off 0 shares
RENAISSANCE TECHNOLOGIES LLC Hedge Fund•Quant	−$198.2K −25.5K shares	$686.5K 88.5K shares
UBS Group AG Institution	−$173.9K −22.4K shares	$66.8K 8.6K shares
J JANE STREET GROUP, LLC Institution	−$151.3K −20.4K shares	Sold Off 0 shares
GSA CAPITAL PARTNERS LLP Hedge Fund•Quant	−$139.6K −18.9K shares	Sold Off 0 shares
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	−$133.0K −18.0K shares	Sold Off 0 shares

Entry and Exit Activity

Institutions that initiated new positions or completely exited MRSN in Q3 2025

New Positions: 3
New Value: $211.1K
Exited Positions: 41
Exited Value: $2.4M

New Positions

Institution	Position Value
D DRW Securities, LLC Institution	$107.5K 13.9K shares
Voleon Capital Management LP Hedge Fund•Quant	$102.4K 13.2K shares
SRS Capital Advisors, Inc. RIA/Wealth	$1.2K 157.0 shares

Exited Positions

Institution	Previous Position
Catalio Capital Management, LP Venture Capital	$464.0K 62.7K shares
GOLDMAN SACHS GROUP INC Institution	$424.4K 57.4K shares
JACOBS LEVY EQUITY MANAGEMENT, INC Hedge Fund•Quant	$394.6K 53.3K shares
J JANE STREET GROUP, LLC Institution	$151.3K 20.4K shares
GSA CAPITAL PARTNERS LLP Hedge Fund•Quant	$139.6K 18.9K shares
SUSQUEHANNA INTERNATIONAL GROUP, LLP Private Equity	$133.0K 18.0K shares
HPM Partners LLC RIA/Wealth	$95.0K 12.8K shares
$DEUTSCHE BANK AG\ logo$ DEUTSCHE BANK AG\ Institution	$91.5K 12.2K shares
NORTHERN TRUST CORP Institution	$65.9K 8.9K shares
Q Qube Research & Technologies Ltd Institution	$45.3K 6.1K shares

Options Activity

Institutions with the largest Call and Put options positions in MRSN as of Q3 2025

Call Positions: 1
Call Value: -
Put Positions: 1
Put Value: -

Call Positions

Institution	Position Value
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	- - contracts

Put Positions

Institution	Position Value
CITADEL ADVISORS LLC Hedge Fund•Multi-Strategy	- - contracts

Most Committed Institutions

Institutions with MRSN as the highest % of their portfolio as of Q3 2025

Institution	Key People	Portfolio Weight	Ownership	Owned Since	Total AUM (Long)
A Alamea Verwaltungs GmbH Institution	-	2.28% $3.3M	8.62% 430.0K shares	Q1 2025 Held for 8 months	$146.4M
L Lion Point Capital, LP Hedge Fund•Event Driven	Carl Didric Marcus Cederholm CIO	1.14% $199.9K	0.52% 25.8K shares	Q1 2025 Held for 8 months	$17.6M
N Nextech Invest, Ltd. Institution	-	0.57% $3.7M	9.67% 482.7K shares	Q1 2025 Held for 8 months	$657.0M
LUMINUS MANAGEMENT LLC Hedge Fund•Sector	Jonathan Dan Barrett CEO	0.35% $388.0K	1.00% 50.0K shares	Q2 2025 Held for 5 months	$110.9M
B Bain Capital Life Sciences Investors, LLC Institution	-	0.18% $2.7M	6.94% 346.5K shares	Q2 2020 Held for 5y 5m	$1.5B
SILVERARC CAPITAL MANAGEMENT, LLC Hedge Fund•Long/Short	Devesh Sharad Gandhi Founder	0.15% $1.0M	2.68% 133.6K shares	Q2 2022 Held for 3y 5m	$689.7M
5 5AM Venture Management, LLC Institution	-	0.15% $405.1K	1.05% 52.2K shares	Q1 2023 Held for 2y 8m	$273.0M
6 683 Capital Management, LLC Hedge Fund•Long/Short	Ari Jonathan Zweiman Managing Partner	0.07% $776.0K	2.00% 100.0K shares	Q3 2024 Held for 1y 2m	$1.1B
Rock Springs Capital Management LP Hedge Fund•Sector	Nnamdi C Etoh CFO	0.07% $1.2M	3.06% 152.6K shares	Q2 2017 Held for 8y 5m	$1.7B
Schonfeld Strategic Advisors LLC Hedge Fund•Multi-Strategy	Ryan Andrew Tolkin CEO	0.01% $2.1M	5.48% 273.6K shares	Q2 2023 Held for 2y 5m	$14.3B