Y-mAbs Therapeutics
YMAB
YMAB was delisted on the 15th of September, 2025.
94 hedge funds and large institutions have $140M invested in Y-mAbs Therapeutics in 2023 Q4 according to their latest regulatory filings, with 11 funds opening new positions, 37 increasing their positions, 32 reducing their positions, and 14 closing their positions.
30% more capital invested
Capital invested by funds: $107M → $140M (+$32.4M)
16% more repeat investments, than reductions
Existing positions increased: 37 | Existing positions reduced: 32
1.88% more ownership
Funds ownership: 45.07% → 46.95% (+1.9%)
6% more call options, than puts
Call options by funds: $17K | Put options by funds: $16K
0% more funds holding in top 10
Funds holding in top 10: 1 → 1 (0)
4% less funds holding
Funds holding: 98 → 94 (-4)
21% less first-time investments, than exits
New positions opened: 11 | Existing positions closed: 14
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
CP
Caligan Partners
New York
|
+$5.93M |
| 2 |
BFM
Boothbay Fund Management
New York
|
+$3.92M |
| 3 |
BlackRock
New York
|
+$2.57M |
| 4 |
Morgan Stanley
New York
|
+$2.21M |
| 5 |
CCIA
Campbell & Co Investment Adviser
Baltimore,
Maryland
|
+$477K |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Millennium Management
New York
|
-$1.88M |
| 2 |
Jacobs Levy Equity Management
Florham Park,
New Jersey
|
-$1.61M |
| 3 |
Citadel Advisors
Miami,
Florida
|
-$1.6M |
| 4 |
AQR Capital Management
Greenwich,
Connecticut
|
-$1.34M |
| 5 |
Prudential Financial
Newark,
New Jersey
|
-$996K |
YMAB Hedge Fund Activity: Q4 2023 in Review
94 of the 6,860 institutional investors tracked by Wall St. Rank reported a position in Y-mAbs Therapeutics (YMAB) for Q4 2023, worth a combined $140M — up 30% from $107M a quarter earlier.
Sellers outnumbered buyers: 14 funds closed out of YMAB and 11 opened new positions — a net loss of 3 holders — while 32 trimmed existing stakes and 37 added.
The largest buyer was Caligan Partners, adding an estimated $5.93M. The largest seller was Millennium Management, cutting an estimated $1.88M.
- 94 institutional investors held Y-mAbs Therapeutics (YMAB) as of Q4 2023, down from 98 in Q3 2023.
- Funds reported $140M of Y-mAbs Therapeutics stock for Q4 2023, up 30% quarter-over-quarter.
- 11 funds opened new Y-mAbs Therapeutics positions in Q4 2023 and 14 closed out, a net change of -3 holders.
- The largest Y-mAbs Therapeutics buyer in Q4 2023 was Caligan Partners, an estimated $5.93M added.
- The largest Y-mAbs Therapeutics seller in Q4 2023 was Millennium Management, an estimated $1.88M sold.
Based on aggregated 13F filings for Q4 2023.