5VM
MRSN

5AM Venture Management’s Mersana Therapeutics MRSN Stock Holding History

5AM Venture Management’s Portfolio MRSN Stock Details MRSN Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2025
Q4 		– Sell
-52,200
Closed -$405K – 25
2025
Q3 		$405K Hold
52,200
– – 0.15% 25
2025
Q2 		$386K Hold
52,200
– – 0.15% 29
2025
Q1 		$449K Hold
52,200
– – 0.17% 31
2024
Q4 		$1.87M Hold
52,200
– – 0.45% 29
2024
Q3 		$2.47M Hold
52,200
– – 0.51% 26
2024
Q2 		$2.62M Hold
52,200
– – 0.59% 25
2024
Q1 		$5.85M Hold
52,200
– – 1.31% 23
2023
Q4 		$3.03M Hold
52,200
– – 0.8% 22
2023
Q3 		$1.66M Hold
52,200
– – 0.48% 24
2023
Q2 		$4.29M Buy
52,200
+4,800
+10% +$702K 1.07% 20
2023
Q1 		$4.87M Buy
+47,400
New +$6.65M 1.25% 18

Other funds holding MRSN

NI
Nextech Invest Zurich, Switzerland $2.11B AUM 413.84% 1-Year Est. Return
BCLSI
Bain Capital Life Sciences Investors Boston, Massachusetts $1.68B AUM 126.09% 1-Year Est. Return
Vanguard Group
Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return
RSCM
Rock Springs Capital Management Baltimore, Maryland $2.05B AUM 161.37% 1-Year Est. Return
AV
Alamea Verwaltungs Edison, New Jersey $125M AUM 27.56% 1-Year Est. Return
Acadian Asset Management
Acadian Asset Management Boston, Massachusetts $84.2B AUM 55.88% 1-Year Est. Return
AAA
Affinity Asset Advisors New York $2.21B AUM 431.26% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
Bank of America
Bank of America Charlotte, North Carolina $1.55T AUM 33.47% 1-Year Est. Return
Millennium Management
Millennium Management New York $276B AUM 44.8% 1-Year Est. Return

5AM Venture Management's MRSN Position: Q4 2025 in Review

5AM Venture Management sold out of Mersana Therapeutics (MRSN) in Q4 2025, closing a stake of 52,200 shares — an estimated $405K sold.

5AM Venture Management first reported a position in MRSN in Q1 2023 and held it in 11 quarters. The position peaked at $5.85M in Q1 2024. 51 funds tracked by Wall St. Rank hold MRSN as of Q4 2025.

  • 5AM Venture Management reported no remaining Mersana Therapeutics position as of Q4 2025 after selling out during the quarter.
  • 5AM Venture Management sold 52,200 Mersana Therapeutics shares in Q4 2025, an estimated $405K.
  • 5AM Venture Management first reported a position in Mersana Therapeutics in Q1 2023 and held it in 11 quarters.
  • 5AM Venture Management's Mersana Therapeutics position peaked at $5.85M in Q1 2024.
  • 51 funds tracked by Wall St. Rank held Mersana Therapeutics as of Q4 2025.

Based on 5AM Venture Management's 13F filing for Q4 2025, filed 17 Feb 2026.