Mersana Therapeutics
MRSN
MRSN was delisted on the 5th of January, 2026.
83 hedge funds and large institutions have $22.9M invested in Mersana Therapeutics in 2025 Q2 according to their latest regulatory filings, with 14 funds opening new positions, 23 increasing their positions, 30 reducing their positions, and 39 closing their positions.
250% more call options, than puts
Call options by funds: $14K | Put options by funds: $4K
0.33% less ownership
Funds ownership: 2.82% → 2.48% (-0.33%)
23% less funds holding
Funds holding: 108 → 83 (-25)
23% less repeat investments, than reductions
Existing positions increased: 23 | Existing positions reduced: 30
24% less capital invested
Capital invested by funds: $30.2M → $22.9M (-$7.31M)
64% less first-time investments, than exits
New positions opened: 14 | Existing positions closed: 39
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Millennium Management
New York
|
+$735K |
| 2 |
Renaissance Technologies
New York
|
+$707K |
| 3 |
LM
Luminus Management
Houston,
Texas
|
+$365K |
| 4 |
Goldman Sachs
New York
|
+$298K |
| 5 |
Two Sigma Investments
New York
|
+$271K |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
BlackRock
New York
|
-$1.6M |
| 2 |
VA
VR Adviser
New York
|
-$1.23M |
| 3 |
State Street
Boston,
Massachusetts
|
-$756K |
| 4 |
SSA
Schonfeld Strategic Advisors
New York
|
-$682K |
| 5 |
Geode Capital Management
Boston,
Massachusetts
|
-$490K |
MRSN Hedge Fund Activity: Q2 2025 in Review
83 of the 7,612 institutional investors tracked by Wall St. Rank reported a position in Mersana Therapeutics (MRSN) for Q2 2025, worth a combined $22.9M — down 24% from $30.2M a quarter earlier.
Sellers outnumbered buyers: 39 funds closed out of MRSN and 14 opened new positions — a net loss of 25 holders — while 30 trimmed existing stakes and 23 added.
The largest buyer was Millennium Management, opening a new position worth an estimated $735K. The largest seller was BlackRock, cutting an estimated $1.6M.
- 83 institutional investors held Mersana Therapeutics (MRSN) as of Q2 2025, down from 108 in Q1 2025.
- Funds reported $22.9M of Mersana Therapeutics stock for Q2 2025, down 24% quarter-over-quarter.
- 14 funds opened new Mersana Therapeutics positions in Q2 2025 and 39 closed out, a net change of -25 holders.
- The largest Mersana Therapeutics buyer in Q2 2025 was Millennium Management, an estimated $735K added.
- The largest Mersana Therapeutics seller in Q2 2025 was BlackRock, an estimated $1.6M sold.
Based on aggregated 13F filings for Q2 2025.