6CM
MRSN

683 Capital Management’s Mersana Therapeutics MRSN Stock Holding History

683 Capital 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
-100,000
Closed -$776K – 245
2025
Q3 		$776K Buy
100,000
+20,400
+26% +$153K 0.04% 123
2025
Q2 		$589K Buy
79,600
+13,600
+21% +$120K 0.04% 118
2025
Q1 		$568K Buy
66,000
+30,000
+83% +$463K 0.04% 126
2024
Q4 		$1.29M Buy
36,000
+28,688
+392% +$1.48M 0.08% 104
2024
Q3 		$345K Buy
+7,312
New +$323K 0.03% 111

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

683 Capital Management's MRSN Position: Q4 2025 in Review

683 Capital Management sold out of Mersana Therapeutics (MRSN) in Q4 2025, closing a stake of 100,000 shares — an estimated $776K sold.

683 Capital Management first reported a position in MRSN in Q3 2024 and held it in 5 quarters. The position peaked at $1.29M in Q4 2024. 51 funds tracked by Wall St. Rank hold MRSN as of Q4 2025.

  • 683 Capital Management reported no remaining Mersana Therapeutics position as of Q4 2025 after selling out during the quarter.
  • 683 Capital Management sold 100,000 Mersana Therapeutics shares in Q4 2025, an estimated $776K.
  • 683 Capital Management first reported a position in Mersana Therapeutics in Q3 2024 and held it in 5 quarters.
  • 683 Capital Management's Mersana Therapeutics position peaked at $1.29M in Q4 2024.
  • 51 funds tracked by Wall St. Rank held Mersana Therapeutics as of Q4 2025.

Based on 683 Capital Management's 13F filing for Q4 2025, filed 17 Feb 2026.