JO
MRSN

John Overdeck’s Mersana Therapeutics MRSN Stock Holding History

John Overdeck’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
-30,688
Closed -$238K – 4290
2025
Q3 		$238K Sell
30,688
-2,243
-7% -$16.8K ﹤0.01% 3312
2025
Q2 		$244K Buy
32,931
+30,785
+1,435% +$271K ﹤0.01% 2858
2025
Q1 		$18.5K Sell
2,146
-6,289
-75% -$97K ﹤0.01% 3110
2024
Q4 		$302K Sell
8,435
-3,574
-30% -$185K ﹤0.01% 2733
2024
Q3 		$567K Sell
12,009
-17,939
-60% -$791K ﹤0.01% 2407
2024
Q2 		$1.5M Buy
29,948
+21,230
+244% +$1.53M ﹤0.01% 1749
2024
Q1 		$976K Buy
8,718
+1,864
+27% +$185K ﹤0.01% 1972
2023
Q4 		$398K Buy
6,854
+891
+15% +$35.8K ﹤0.01% 2569
2023
Q3 		$189K Sell
5,963
-4,728
-44% -$225K ﹤0.01% 2651
2023
Q2 		$879K Buy
10,691
+2,508
+31% +$367K ﹤0.01% 2007
2023
Q1 		$841K Sell
8,183
-16,530
-67% -$2.32M ﹤0.01% 1956
2022
Q4 		$3.62M Sell
24,713
-2,570
-9% -$434K 0.01% 1017
2022
Q3 		$4.61M Buy
27,283
+9,236
+51% +$1.5M 0.02% 789
2022
Q2 		$2.08M Sell
18,047
-32,978
-65% -$3.1M 0.01% 1181
2022
Q1 		$5.09M Buy
51,025
+15,915
+45% +$1.86M 0.02% 921
2021
Q4 		$5.46M Buy
35,110
+21,180
+152% +$4.12M 0.01% 1148
2021
Q3 		$3.28M Sell
13,930
-8,631
-38% -$2.52M 0.01% 1540
2021
Q2 		$7.66M Buy
22,561
+7,138
+46% +$2.7M 0.02% 961
2021
Q1 		$6.24M Buy
15,423
+7,490
+94% +$3.63M 0.02% 928
2020
Q4 		$5.28M Buy
7,933
+1,222
+18% +$680K 0.02% 902
2020
Q3 		$3.12M Sell
6,711
-2,064
-24% -$1.04M 0.01% 1048
2020
Q2 		$5.13M Buy
8,775
+5,727
+188% +$1.96M 0.03% 632
2020
Q1 		$444K Buy
3,048
+1,820
+148% +$318K ﹤0.01% 2027
2019
Q4 		$176K Sell
1,228
-3,438
-74% -$251K ﹤0.01% 3450
2019
Q3 		$184K Buy
4,666
+3,481
+294% +$253K ﹤0.01% 3215
2019
Q2 		$120K Sell
1,185
-1,567
-57% -$185K ﹤0.01% 3181
2019
Q1 		$362K Buy
2,752
+35
+1% +$4.4K ﹤0.01% 2474
2018
Q4 		$277K Buy
+2,717
New +$430K ﹤0.01% 2506

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

John Overdeck's MRSN Position: Q4 2025 in Review

John Overdeck sold out of Mersana Therapeutics (MRSN) in Q4 2025, closing a stake of 30,688 shares — an estimated $238K sold.

John Overdeck first reported a position in MRSN in Q4 2018 and held it in 28 quarters. The position peaked at $7.66M in Q2 2021. 51 funds tracked by Wall St. Rank hold MRSN as of Q4 2025.

  • John Overdeck reported no remaining Mersana Therapeutics position as of Q4 2025 after selling out during the quarter.
  • John Overdeck sold 30,688 Mersana Therapeutics shares in Q4 2025, an estimated $238K.
  • John Overdeck first reported a position in Mersana Therapeutics in Q4 2018 and held it in 28 quarters.
  • John Overdeck's Mersana Therapeutics position peaked at $7.66M in Q2 2021.
  • 51 funds tracked by Wall St. Rank held Mersana Therapeutics as of Q4 2025.

Based on Two Sigma Investments's 13F filing for Q4 2025, filed 17 Feb 2026.