Citadel Advisors’s Mersana Therapeutics MRSN Stock Holding History

Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake
Trade Value Portfolio Weight Portfolio Position
2025
Q3
Sell
-560
Closed -$4.14K 13621
2025
Q2
$4.14K Buy
560
+40
+8% +$351 ﹤0.01% 12245
2025
Q1
$4.47K Buy
520
+132
+34% +$2.04K ﹤0.01% 13890
2024
Q4
$13.9K Sell
388
-700
-64% -$36.2K ﹤0.01% 13426
2024
Q3
$51.4K Buy
1,088
+300
+38% +$13.2K ﹤0.01% 11879
2024
Q2
$39.6K Buy
788
+644
+447% +$46.6K ﹤0.01% 12004
2024
Q1
$16.1K Sell
144
-344
-70% -$34.2K ﹤0.01% 13152
2023
Q4
$28.3K Sell
488
-1,444
-75% -$58.1K ﹤0.01% 12310
2023
Q3
$61.3K Sell
1,932
-2,320
-55% -$110K ﹤0.01% 11502
2023
Q2
$350K Buy
4,252
+4,056
+2,069% +$593K ﹤0.01% 8701
2023
Q1
$20.1K Buy
+196
New +$27.5K ﹤0.01% 13065
2022
Q3
Sell
-524
Closed -$61K 13241
2022
Q2
$61K Sell
524
-124
-19% -$11.7K ﹤0.01% 11806
2022
Q1
$65K Sell
648
-1,176
-64% -$137K ﹤0.01% 12621
2021
Q4
$284K Sell
1,824
-216
-11% -$42K ﹤0.01% 11045
2021
Q3
$481K Buy
2,040
+1,156
+131% +$338K ﹤0.01% 9970
2021
Q2
$300K Sell
884
-2,184
-71% -$827K ﹤0.01% 11276
2021
Q1
$1.24M Sell
3,068
-3,108
-50% -$1.51M ﹤0.01% 7562
2020
Q4
$4.11M Buy
6,176
+5,160
+508% +$2.87M ﹤0.01% 4005
2020
Q3
$473K Buy
1,016
+264
+35% +$133K ﹤0.01% 7393
2020
Q2
$440K Buy
+752
New +$257K ﹤0.01% 7306

Other funds holding MRSN

Citadel Advisors's MRSN Position: Q1 2026 in Review

Citadel Advisors sold out of Mersana Therapeutics (MRSN) in Q1 2026, closing a stake of 22,493 shares — an estimated $651K sold.

Citadel Advisors first reported a position in MRSN in Q2 2017 and held it in 27 quarters. The position peaked at $52M in Q4 2020. 1 fund tracked by Wall St. Rank holds MRSN as of Q1 2026.

  • Citadel Advisors reported no remaining Mersana Therapeutics position as of Q1 2026 after selling out during the quarter.
  • Citadel Advisors sold 22,493 Mersana Therapeutics shares in Q1 2026, an estimated $651K.
  • Citadel Advisors first reported a position in Mersana Therapeutics in Q2 2017 and held it in 27 quarters.
  • Citadel Advisors's Mersana Therapeutics position peaked at $52M in Q4 2020.
  • 1 fund tracked by Wall St. Rank held Mersana Therapeutics as of Q1 2026.

Based on Citadel Advisors's 13F filing for Q1 2026, filed 15 May 2026.