Hudson Bay Capital Management LP
Position in ALNY — Alnylam Pharmaceuticals, Inc.
CIK 1393825
STAMFORD, CT
Position in ALNY
as of Jun 30, 2026
· filed Aug 14, 2026
Position Value
$44,769,181
+$31,534,381 QoQ
Shares Held
148,720
+271.8% QoQ
Ownership
0.111%
of shares outstanding
% of Portfolio
0.24%
of 13F equity value
Holder Rank
#90
of 764 holders
Holding Since
Dec 2020
13 quarters on record
Voting authority
Sole 100%
Shared 0%
None 0%
Common Shares in ALNY Over Time
Shares Held
Position Value (USD)
Derivatives in ALNY
reported options exposure · as of Dec 31, 2025CallValue
$0
CallShares
0
PutValue
$79,530,000
PutShares
200,000
Notional value of option positions as reported on Form 13F. Calls and puts are disclosed separately and do not net against the common-share stake above.
Position in Biotechnology
Healthcare · as of Jun 30, 2026Hudson Bay Capital Management LP holds $565,779,637 across 77 Biotechnology names. ALNY ranks #3 (7.9% of the industry book) .
| # | 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.
This page
|
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 ALNY
Export CSV
17 filing rows on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-06-30 | $44,769,181 | 148,720 | Shares | Sole | 2026-08-14 | |
| 2026-03-31 | $13,234,800 | 40,000 | Shares | Sole | 2026-05-13 | |
| 2025-12-31 | $79,530,000 | 200,000 | Put | Sole | 2026-02-13 | |
| 2025-12-31 | $33,800,250 | 85,000 | Shares | Sole | 2026-02-13 | |
| 2025-09-30 | $4,291,416 | 9,411 | Shares | Sole | 2025-12-15 | |
| 2025-06-30 | $5,004,829 | 15,348 | Shares | Sole | 2025-08-18 | |
| 2025-03-31 | $10,800,800 | 40,000 | Put | Sole | 2025-05-14 | |
| 2024-12-31 | $1,764,825 | 7,500 | Shares | Sole | 2025-02-14 | |
| 2024-09-30 | $5,022,597 | 18,262 | Shares | Sole | 2024-11-13 | |
| 2024-06-30 | $23,085,000 | 95,000 | Put | Sole | 2024-08-14 | |
| 2024-06-30 | $7,290,000 | 30,000 | Shares | Sole | 2024-08-14 | |
| 2024-03-31 | $4,483,500 | 30,000 | Call | Sole | 2024-05-15 | |
| 2024-03-31 | $18,307,625 | 122,500 | Shares | Sole | 2024-05-15 | |
| 2023-12-31 | $15,791,325 | 82,500 | Shares | Sole | 2024-02-14 | |
| 2023-09-30 | $8,128,890 | 45,900 | Shares | Sole | 2023-11-14 | |
| 2023-09-30 | $3,524,290 | 19,900 | Call | Sole | 2023-11-14 | |
| 2020-12-31 | $2,599,400 | 20,000 | Shares | Sole | 2021-02-12 | |
| No filing history on record for this holder in this stock. | ||||||