Institutional Manager · CIK 0001587114
EcoR1 Capital, LLC
San Francisco, CA · File #028-16764
Latest AUM
$2.20B
Positions
30
Top-10 Concentration
84.6%
Filings
9
Portfolio Value Over Time
2024-03
2024-06
2024-09
2024-12
2025-03
2025-06
2025-09
2025-12
Biggest QoQ Changes
Ranked by conviction flow (share change × current price) so mark-to-market moves don't dominate. Price effect column shows how much of the $ change was just the stock moving.
| Action | Issuer | Ticker / CUSIP | Δ Shares | Flow ($) | Price Effect |
|---|---|---|---|---|---|
| EXITED | UNIQURE NV | N90064101 | -3,988,971 | -$232.8M | $0 |
| REDUCE | XENCOR INC | XNCR | -6,077,267 | -$93.0M | +$22.0M |
| EXITED | TANGO THERAPEUTICS INC | 87583X109 | -10,630,736 | -$89.3M | $0 |
| EXITED | APELLIS PHARMACEUTICALS INC | 03753U106 | -3,447,156 | -$78.0M | $0 |
| ADD | CENTESSA PHARMACEUTICALS PLC | CNTA | +2,565,000 | +$64.2M | +$418,000 |
| EXITED | MADRIGAL PHARMACEUTICALS INC | 558868105 | -75,000 | -$34.4M | $0 |
| EXITED | AVIDITY BIOSCIENCES INC | 05370A108 | -765,000 | -$33.3M | $0 |
| NEW | ZENAS BIOPHARMA INC | ZBIO | +789,500 | +$28.7M | $0 |
| REDUCE | IMMUNOME INC | IMNM | -1,223,825 | -$26.3M | +$39.9M |
| NEW | STRUCTURE THERAPEUTICS INC | GPCR | +334,380 | +$23.3M | $0 |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 202530 pos · $2.20B
- 13F HOLDINGS REPORTQ/E Sep 202530 pos · $2.08B
- 13F HOLDINGS REPORTQ/E Jun 202537 pos · $1.69B
- 13F HOLDINGS REPORTQ/E Mar 202546 pos · $1.69B
- 13F HOLDINGS REPORTQ/E Dec 202459 pos · $2.65B
- 13F HOLDINGS REPORTQ/E Sep 202464 pos · $2.92B
- 13F HOLDINGS REPORTQ/E Jun 202455 pos · $3.27B
- 13F HOLDINGS REPORTQ/E Mar 202459 pos · $3.95B
- 13F HOLDINGS REPORTQ/E Dec 202351 pos · $2.96B
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | ZYMEWORKS INC | ZYME | 22,970,388 | $604.8M | 27.44% |
| 2 | ANAPTYSBIO INC | ANABV | 7,880,094 | $382.0M | 17.33% |
| 3 | JAZZ PHARMACEUTICALS PLC | JAZZ | 1,706,469 | $290.1M | 13.16% |
| 4 | CRINETICS PHARMACEUTICALS IN | CRNX | 4,288,120 | $199.6M | 9.06% |
| 5 | CENTESSA PHARMACEUTICALS PLC | CNTA | 3,115,000 | $77.9M | 3.53% |
| 6 | CRISPR THERAPEUTICS AG | CRSP | 1,389,276 | $72.9M | 3.31% |
| 7 | MBX BIOSCIENCES INC | MBX | 2,123,604 | $67.0M | 3.04% |
| 8 | IMMUNOME INC | IMNM | 2,855,590 | $61.3M | 2.78% |
| 9 | ORIC PHARMACEUTICALS INC | ORIC | 6,728,116 | $55.0M | 2.50% |
| 10 | GALAPAGOS NV | GLPGF | 1,667,119 | $54.5M | 2.47% |
| 11 | XENCOR INC | XNCR | 3,251,112 | $49.8M | 2.26% |
| 12 | BRIDGEBIO ONCOLOGY THERAPEUT | BBOT | 2,823,126 | $35.3M | 1.60% |
| 13 | ETON PHARMACEUTICALS INC | ETON | 2,030,544 | $34.3M | 1.56% |
| 14 | CG ONCOLOGY INC | CGON | 772,000 | $32.1M | 1.45% |
| 15 | ZENAS BIOPHARMA INC | ZBIO | 789,500 | $28.7M | 1.30% |
| 16 | NEUROGENE INC | NGNE | 1,271,342 | $26.2M | 1.19% |
| 17 | STRUCTURE THERAPEUTICS INC | GPCR | 334,380 | $23.3M | 1.06% |
| 18 | VAXCYTE INC | PCVX | 450,000 | $20.8M | 0.94% |
| 19 | AQUESTIVE THERAPEUTICS INC | AQST | 2,625,000 | $17.0M | 0.77% |
| 20 | VOYAGER THERAPEUTICS INC | VYGR | 4,002,847 | $15.7M | 0.71% |