Hudson Bay Capital Management LP
Position in RYTM — Rhythm Pharmaceuticals, Inc.
CIK 1393825
STAMFORD, CT
Position in RYTM
as of Mar 31, 2026
· filed May 13, 2026
Position Value
$793,166
-$3,963,771 QoQ
Shares Held
9,120
-95.6% QoQ
Ownership
0.013%
of shares outstanding
% of Portfolio
0.01%
of 13F equity value
Holder Rank
—
not a current holder
Holding Since
Sep 2023
2 quarters on record
Voting authority
Sole 100%
Shared 0%
None 0%
Common Shares in RYTM Over Time
Shares Held
Position Value (USD)
Position in Biotechnology
Healthcare · as of Jun 30, 2026Hudson Bay Capital Management LP holds $565,820,903 across 77 Biotechnology names.
| # | Ticker | Company | Shares | Value (USD) | Open |
|---|---|---|---|---|---|
| 1 | VRTX |
Vertex Pharmaceuticals Inc / Ma
|
390,440 | $193,943,261 | |
| 2 | BMRN |
Biomarin Pharmaceutical Inc
|
825,002 | $47,206,614 | |
| 3 | ALNY |
Alnylam Pharmaceuticals, Inc.
|
148,720 | $44,769,181 | |
| 4 | BNTX |
BioNTech SE
|
260,000 | $24,193,000 | |
| 5 | IMCR |
Immunocore Holdings plc
|
590,000 | $18,732,500 | |
| 6 | TECH |
BIO-TECHNE Corp
|
200,000 | $14,130,000 | |
| 7 | VIR |
Vir Biotechnology, Inc.
|
1,364,000 | $13,899,160 | |
| 8 | PTCT |
Ptc Therapeutics, Inc.
|
159,778 | $13,033,091 |
All Filings in RYTM
Export CSV
2 filing rows on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-03-31 | $793,166 | 9,120 | Shares | Defined | 2026-05-13 | |
| 2023-09-30 | $4,756,937 | 207,500 | Shares | Sole | 2023-11-14 | |
| No filing history on record for this holder in this stock. | ||||||