13F FILER • PETER KOLCHINSKY
RA Capital Management
Peter Kolchinsky — RA CAPITAL MANAGEMENT, L.P.
No writing by this manager has been read and indexed yet, so this page carries the filings only. Holdings come straight from the Form 13F-HR on EDGAR.
84
Positions
$11.5B
Reported Value
60.4%
In Top 10
—
Claims Indexed
Largest reported positions
RA CAPITAL MANAGEMENT, L.P. • CIK 0001346824 • 2026-06-30 • FILED 2026-08-14
WHAT CHANGED THIS QUARTER
In its Q2 2026 13F, filed Aug 14, 2026, RA Capital Management reported 84 positions worth $11.5B in US-listed stock. The largest stock position is Ascendis Pharma A/S at 23.8% of the reported book, and the ten largest lines of any type make up 60.4% of it.
It opened 17 new positions, the largest stock positions being Ascendis Pharma A/S ($2.7B), Parabilis Medicines Inc ($791.9M) and Hemab Therapeutics Holdings ($286.8M), and exited 18, the largest stock exits being Ascendis Pharma A/S - Adr ($2.4B last quarter), Dianthus Therapeutics Inc ($219.2M last quarter) and Praxis Precision Medicines I ($120.4M last quarter).
Among positions it already held, the biggest increases by share count were Aclaris Therapeutics Inc (+87%), Artiva Biotherapeutics Inc (+82%) and Solid Biosciences Inc (+29%), and the biggest cuts were Nuvalent Inc-A (−51%), Geron Corp (−33%) and Edgewise Therapeutics Inc (−19%).
| Issuer | Value | Weight | Shares QoQ |
|---|---|---|---|
| ASCENDIS PHARMA A/S | $2.7B | 23.8% | New |
| PARABILIS MEDICINES INC | $791.9M | 6.9% | New |
| RHYTHM PHARMACEUTICALS INC | $740.2M | 6.4% | — |
| VAXCYTE INC | $667.0M | 5.8% | — |
| SIONNA THERAPEUTICS INC | $435.7M | 3.8% | — |
| TYRA BIOSCIENCES INC | $389.6M | 3.4% | — |
| EDGEWISE THERAPEUTICS INC | $341.0M | 3.0% | -20% |
| NEWAMSTERDAM PHARMA CO NV | $323.7M | 2.8% | — |
| HEMAB THERAPEUTICS HOLDINGS | $286.8M | 2.5% | New |
| SEPTERNA INC | $234.3M | 2.0% | — |
| BICARA THERAPEUTICS INC | $215.4M | 1.9% | — |
| MINERALYS THERAPEUTICS INC | $207.6M | 1.8% | — |
| GH RESEARCH PLC | $205.3M | 1.8% | -1% |
| DISC MEDICINE INC | $179.2M | 1.6% | — |
| SPYGLASS PHARMA INC | $178.6M | 1.6% | — |
| ARTIVA BIOTHERAPEUTICS INC | $174.2M | 1.5% | +82% |
| JANUX THERAPEUTICS INC | $171.9M | 1.5% | — |
| TAYSHA GENE THERAPIES INC | $160.4M | 1.4% | — |
| BIOCRYST PHARMACEUTICALS INC | $158.3M | 1.4% | — |
| WAVE LIFE SCIENCES LTD | $156.7M | 1.4% | — |
20 of 84 positions. A 13F covers long US-listed positions at a quarter end only — no shorts, leverage, cash, ordinary bonds or private holdings — and is 45 days old on publication.
NEW POSITIONS
- Ascendis Pharma A/S$2.7B · 23.8%
- Parabilis Medicines Inc$791.9M · 6.9%
- Hemab Therapeutics Holdings$286.8M · 2.5%
- Abivax Sa-Adr$150.9M · 1.3%
- Oruka Therapeutics Inc$148.0M · 1.3%
EXITS
- Ascendis Pharma A/S - Adr$2.4B last quarter
- Dianthus Therapeutics Inc$219.2M last quarter
- Praxis Precision Medicines I$120.4M last quarter
- Sarepta Therapeutics Inc$84.9M last quarter
- Spyre Therapeutics Inc$81.8M last quarter
QUESTIONS PEOPLE ASK
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