Y-mAbs Therapeutics
YMAB
YMAB was delisted on the 15th of September, 2025.
117 hedge funds and large institutions have $804M invested in Y-mAbs Therapeutics in 2021 Q1 according to their latest regulatory filings, with 18 funds opening new positions, 55 increasing their positions, 32 reducing their positions, and 14 closing their positions.
72% more repeat investments, than reductions
Existing positions increased: 55 | Existing positions reduced: 32
29% more first-time investments, than exits
New positions opened: 18 | Existing positions closed: 14
5.43% more ownership
Funds ownership: 55.47% → 60.91% (+5.4%)
3% more funds holding
Funds holding: 114 → 117 (+3)
28% less capital invested
Capital invested by funds: $1.11B → $804M (-$308M)
50% less funds holding in top 10
Funds holding in top 10: 4 → 2 (-2)
100% less call options, than puts
Call options by funds: $0 | Put options by funds: $496K
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
State Street
Boston,
Massachusetts
|
+$31.4M |
| 2 |
Wellington Management Group
Boston,
Massachusetts
|
+$23.8M |
| 3 |
Fidelity Investments
Boston,
Massachusetts
|
+$22.2M |
| 4 |
FLAM
First Light Asset Management
Edina,
Minnesota
|
+$12.7M |
| 5 |
ACM
Ashford Capital Management
Wilmington,
Delaware
|
+$11.8M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
PCH
Polar Capital Holdings
London,
United Kingdom
|
-$20.5M |
| 2 |
CAM
Cormorant Asset Management
Boston,
Massachusetts
|
-$17.7M |
| 3 |
SFM
Sphera Funds Management
Tel Aviv,
Israel
|
-$6.49M |
| 4 |
PI
Putnam Investments
Boston,
Massachusetts
|
-$5.7M |
| 5 |
Axa
Paris,
France
|
-$4.68M |
YMAB Hedge Fund Activity: Q1 2021 in Review
117 of the 5,696 institutional investors tracked by Wall St. Rank reported a position in Y-mAbs Therapeutics (YMAB) for Q1 2021, worth a combined $804M — down 28% from $1.11B a quarter earlier.
Buyers outnumbered sellers: 18 funds opened new YMAB positions and 14 closed out — a net gain of 4 holders — while 55 added to existing stakes and 32 trimmed.
The largest buyer was State Street, adding an estimated $31.4M. The largest seller was Polar Capital Holdings, cutting an estimated $20.5M.
- 117 institutional investors held Y-mAbs Therapeutics (YMAB) as of Q1 2021, up from 114 in Q4 2020.
- Funds reported $804M of Y-mAbs Therapeutics stock for Q1 2021, down 28% quarter-over-quarter.
- 18 funds opened new Y-mAbs Therapeutics positions in Q1 2021 and 14 closed out, a net change of +4 holders.
- The largest Y-mAbs Therapeutics buyer in Q1 2021 was State Street, an estimated $31.4M added.
- The largest Y-mAbs Therapeutics seller in Q1 2021 was Polar Capital Holdings, an estimated $20.5M sold.
Based on aggregated 13F filings for Q1 2021.