Hudson Bay Capital Management LP
Position in XFOR — X4 Pharmaceuticals, Inc
CIK 1393825
STAMFORD, CT
Position in XFOR
as of Mar 31, 2026
· filed May 13, 2026
Position Value
$207,685
+$78,729 QoQ
Shares Held
50,287
+56.0% QoQ
Ownership
0.053%
of shares outstanding
% of Portfolio
0.00%
of 13F equity value
Holder Rank
—
not a current holder
Holding Since
Dec 2025
2 quarters on record
Voting authority
Sole 100%
Shared 0%
None 0%
Common Shares in XFOR Over Time
Shares Held
Position Value (USD)
Position in Biotechnology
Healthcare · as of Mar 31, 2026Hudson Bay Capital Management LP holds $535,016,974 across 151 Biotechnology names. XFOR ranks #118 (0.0% of the industry book) .
| # | Ticker | Company | Shares | Value (USD) | Open |
|---|---|---|---|---|---|
| 1 | BMRN |
Biomarin Pharmaceutical Inc
|
974,776 | $55,065,096 | |
| 2 | APLS |
Apellis Pharmaceuticals, Inc.
|
1,190,416 | $47,890,435 | |
| 3 | REGN |
Regeneron Pharmaceuticals, Inc.
|
32,001 | $24,725,252 | |
| 4 | BNTX |
BioNTech SE
|
275,000 | $24,442,000 | |
| 5 | IONS |
Ionis Pharmaceuticals Inc
|
295,100 | $22,159,059 | |
| 6 | ARGX |
Argenx SE
|
30,000 | $21,907,500 | |
| 7 | VRTX |
Vertex Pharmaceuticals Inc / Ma
|
45,000 | $20,094,300 | |
| 8 | IMCR |
Immunocore Holdings plc
|
633,174 | $19,090,196 |
All Filings in XFOR
Export CSV
2 filing rows on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-03-31 | $207,685 | 50,287 | Shares | Defined | 2026-05-13 | |
| 2025-12-31 | $128,956 | 32,239 | Shares | Defined | 2026-02-13 | |
| No filing history on record for this holder in this stock. | ||||||