Investor
EcoR1 Capital, LLC
CIK 0001587114 · filed 2026-05-15 · SEC filing
13F book
$2.36B
Positions
29
10 new · 9 sold
Largest name
24.4%
Zymeworks Inc. · ZYME
Est. mark
$80.4M
Price effect on 19 names still held. Flow $68.7M.
| Name | Ticker | Shares | Value | Weight | Est. mark | Change |
|---|---|---|---|---|---|---|
| Zymeworks Inc. | ZYME | 23M | $575.2M | 24.4% | −$29.6M | Held |
| Anaptysbio, Inc | ANAB | 7.88M | $437M | 18.5% | $55M | Held |
| Jazz Pharmaceuticals Plc | JAZZ | 1.71M | $322.6M | 13.7% | $32.5M | Held |
| Centessa Pharmaceuticals Plc | — | 6M | $238.3M | 10.1% | $45.8M | Added$160.4M |
| Crinetics Pharmaceuticals In | — | 4.29M | $155.7M | 6.6% | −$43.9M | Held |
| Aktis Oncology, Inc. | AKTS | 4.82M | $86.3M | 3.7% | — | New |
| Oric Pharmaceuticals, Inc. | ORIC | 6.73M | $85.2M | 3.6% | $30.2M | Held |
| CG Oncology, Inc. | CGON | 1.1M | $74.6M | 3.2% | $20.2M | Added$42.5M |
| Crispr Therapeutics Ag | CRSP | 1.39M | $66.1M | 2.8% | −$6.77M | Held |
| Eton Pharmaceuticals, Inc. | ETON | 2.17M | $53.6M | 2.3% | $15.8M | Added$19.3M |
| Galapagos Nv | — | 1.67M | $50M | 2.1% | −$4.5M | Held |
| Xencor Inc | XNCR | 2.18M | $26.3M | 1.1% | −$7.09M | Cut−$23.4M |
| Neurogene Inc. | NGNE | 1.27M | $25.6M | 1.1% | −$559.4K | Held |
| Bridgebio Oncology Therapeut | — | 2.82M | $25.3M | 1.1% | −$10.1M | Held |
| MBX Biosciences, Inc. | MBX | 777K | $23.2M | 1.0% | −$1.31M | Cut−$43.8M |
| Relay Therapeutics, Inc. | RLAY | 1.9M | $19M | 0.8% | — | New |
| Zenas BioPharma, Inc. | ZBIO | 789.5K | $15.4M | 0.7% | −$13.2M | Held |
| Erasca, Inc. | ERAS | 900K | $14.6M | 0.6% | — | New |
| Eikon Therapeutics, Inc. | EIKN | 732.6K | $7.75M | 0.3% | — | New |
| Replimune Group, Inc. | REPL | 1M | $7.65M | 0.3% | — | New |
| Zura Bio Ltd | ZURA | 1.18M | $7.02M | 0.3% | — | New |
| Phathom Pharmaceuticals, Inc. | PHAT | 625K | $6.94M | 0.3% | — | New |
| Mereo Biopharma Group Plc | MREO | 13.4M | $4.41M | 0.2% | −$681.2K | Added$1.14M |
| Stoke Therapeutics, Inc. | STOK | 100K | $3.26M | 0.1% | — | New |
| Prelude Therapeutics Inc | PRLD | 947K | $3.24M | 0.1% | — | New |
| iBio, Inc. | IBIO | 1.58M | $3.01M | 0.1% | −$47.5K | Cut−$1.29M |
| Helix Acquisition Corp. III | HLXC | 200K | $2.03M | 0.1% | — | New |
| Atara Biotherapeutics, Inc. | ATRA | 99.6K | $471.1K | 0.0% | −$1.33M | Cut−$9.9M |
| Surrozen Inc | — | 4.44K | $129.5K | 0.0% | $29K | Held |
Positions as of Q1 2026. 13F filings arrive up to 45 days after quarter-end and omit shorts. Values are quarter-end marks, as filed. Estimated mark is the price effect on shares still held — not realized P&L or investment advice.