EC
MRSN

EcoR1 Capital’s Mersana Therapeutics MRSN Stock Holding History

EcoR1 Capital’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
Q1 		– Sell
-453,120
Closed -$16.2M – 59
2024
Q4 		$16.2M Sell
453,120
-321,468
-42% -$16.6M 0.65% 31
2024
Q3 		$36.6M Hold
774,588
– – 1.25% 20
2024
Q2 		$38.9M Hold
774,588
– – 1.19% 22
2024
Q1 		$86.8M Hold
774,588
– – 2.2% 16
2023
Q4 		$44.9M Hold
774,588
– – 1.17% 16
2023
Q3 		$24.6M Buy
+774,588
New +$36.8M 0.84% 24
2022
Q3 		– Sell
-12,438
Closed -$1.44M – 85
2022
Q2 		$1.44M Sell
12,438
-625
-5% -$58.8K 0.05% 66
2022
Q1 		$1.3M Buy
+13,063
New +$1.53M 0.04% 73
2019
Q3 		– Sell
-55,689
Closed -$5.64M – 42
2019
Q2 		$5.64M Sell
55,689
-36,311
-39% -$4.28M 0.58% 27
2019
Q1 		$12.1M Buy
+92,000
New +$11.6M 1.31% 25
2018
Q4 		– Sell
-19,825
Closed -$4.96M – 58
2018
Q3 		$4.96M Buy
+19,825
New +$6.64M 0.51% 36

Other funds holding MRSN

NI
Nextech Invest Zurich, Switzerland $1.42B AUM 304.47% 1-Year Est. Return
BCLSI
Bain Capital Life Sciences Investors Boston, Massachusetts $1.11B AUM 171.34% 1-Year Est. Return
Vanguard Group
Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return
BlackRock
BlackRock New York $5.7T AUM 30.48% 1-Year Est. Return
SSA
Schonfeld Strategic Advisors New York $12.3B AUM 37.17% 1-Year Est. Return
AQR Capital Management
AQR Capital Management Greenwich, Connecticut $218B AUM 29.41% 1-Year Est. Return
RSCM
Rock Springs Capital Management Baltimore, Maryland $1.7B AUM 93.03% 1-Year Est. Return
VA
VR Adviser New York $2.68B AUM 422.73% 1-Year Est. Return
SCM
Silverarc Capital Management Boston, Massachusetts $849M AUM 470.8% 1-Year Est. Return
Acadian Asset Management
Acadian Asset Management Boston, Massachusetts $70.5B AUM 36% 1-Year Est. Return