Mersana Therapeutics
MRSN
MRSN was delisted on the 5th of January, 2026.
132 hedge funds and large institutions have $1.14B invested in Mersana Therapeutics in 2021 Q1 according to their latest regulatory filings, with 18 funds opening new positions, 55 increasing their positions, 45 reducing their positions, and 36 closing their positions.
22% more repeat investments, than reductions
Existing positions increased: 55 | Existing positions reduced: 45
11% more call options, than puts
Call options by funds: $10.8M | Put options by funds: $9.73M
0.03% more ownership
Funds ownership: 4.03% → 4.06% (+0.03%)
13% less funds holding
Funds holding: 151 → 132 (-19)
38% less capital invested
Capital invested by funds: $1.83B → $1.14B (-$690M)
50% less funds holding in top 10
Funds holding in top 10: 6 → 3 (-3)
50% less first-time investments, than exits
New positions opened: 18 | Existing positions closed: 36
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Westfield Capital Management
Boston,
Massachusetts
|
+$29.8M |
| 2 |
Wellington Management Group
Boston,
Massachusetts
|
+$29.6M |
| 3 |
O
OrbiMed
New York
|
+$21.7M |
| 4 |
SCM
Sarissa Capital Management
Greenwich,
Connecticut
|
+$20.9M |
| 5 |
BG
Bellevue Group
Kuesnacht,
Switzerland
|
+$17.9M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
CCM
Consonance Capital Management
New York
|
-$37.3M |
| 2 |
Citadel Advisors
Miami,
Florida
|
-$27.5M |
| 3 |
Janus Henderson Group
London,
|
-$24.5M |
| 4 |
Invesco
Atlanta,
Georgia
|
-$17.8M |
| 5 |
GPP
Great Point Partners
Greenwich,
Connecticut
|
-$13M |
MRSN Hedge Fund Activity: Q1 2021 in Review
132 of the 5,711 institutional investors tracked by Wall St. Rank reported a position in Mersana Therapeutics (MRSN) for Q1 2021, worth a combined $1.14B — down 38% from $1.83B a quarter earlier.
Sellers outnumbered buyers: 36 funds closed out of MRSN and 18 opened new positions — a net loss of 18 holders — while 45 trimmed existing stakes and 55 added.
The largest buyer was Westfield Capital Management, adding an estimated $29.8M. The largest seller was Consonance Capital Management, exiting entirely with an estimated $37.3M sold.
- 132 institutional investors held Mersana Therapeutics (MRSN) as of Q1 2021, down from 151 in Q4 2020.
- Funds reported $1.14B of Mersana Therapeutics stock for Q1 2021, down 38% quarter-over-quarter.
- 18 funds opened new Mersana Therapeutics positions in Q1 2021 and 36 closed out, a net change of -18 holders.
- The largest Mersana Therapeutics buyer in Q1 2021 was Westfield Capital Management, an estimated $29.8M added.
- The largest Mersana Therapeutics seller in Q1 2021 was Consonance Capital Management, an estimated $37.3M sold.
Based on aggregated 13F filings for Q1 2021.