EcoR1 Capital, LLC
13F filer · CIK 1587114 · San Francisco, CA
Summary
EcoR1 Capital, LLC reported $2.06B across 33 positions in its 13F for 2026 Q2, filed Aug 14, 2026. The largest holdings are ZYME (29.2%), ANAB (25.9%), AKTS (7.6%). Versus 2026 Q1, leaving options aside, it opened 9 new positions, added to 3, trimmed 4 and sold out of 7.
Reported value$2.06B
Positions33incl. options
Report period2026 Q2
FiledAug 14, 2026
New positions9
Added3
Trimmed4
Sold out7
Top 25 holdings
By reported value, options listed separately · change vs 2026 Q1
Weight 29.2%Value $600.45MPrice $27.20Shares 22.97MSince Jun 30 +4.06%
Weight 25.9%Value $531.91MPrice $50.37Shares 7.88MSince Jun 30 -25.38%
Weight 7.6%Value $155.49MPrice $19.69Shares 4.82MSince Jun 30 -38.91%
Weight 5.2%Value $106.17MPrice $70.52Shares 1.49M +35.60%Since Jun 30 -0.75%
Weight 3.8%Value $78.62MPrice $59.19Shares 2.17MSince Jun 30 +63.51%
Weight 3.7%Value $75.77MPrice $56.00Shares 1.39MSince Jun 30 +2.68%
Weight 3.5%Value $72.87MPrice $13.37Shares 6.73MSince Jun 30 +23.45%
Weight 3.1%Value $63.87MPrice $35.98Shares 3.17MSince Jun 30 +78.83%
Weight 2.4%Value $49.98MPrice $29.52Shares 1.67MSince Jun 30 -1.53%
Weight 1.9%Value $39.98MPrice $28.39Shares 1.27MSince Jun 30 -9.73%
Weight 1.2%Value $24.05MPrice $25.88Shares 735K +635.00%Since Jun 30 -20.90%
Weight 1.2%Value $23.97MPrice $3.70Shares 6.55MSince Jun 30 +1.09%
Weight 1.1%Value $23.10MPrice $18.82Shares 800KSince Jun 30 -34.83%
Weight 1.0%Value $21.51MPrice $3.92Shares 2.82MSince Jun 30 -48.56%
Weight 1.0%Value $21.45MPrice $57.75Shares 389K -50.00%Since Jun 30 +4.62%
Weight 1.0%Value $20.04MPrice $26.76Shares 790KSince Jun 30 +5.44%
Weight 0.9%Value $17.82MPrice $8.05Shares 1.55M +1458.34%Since Jun 30 -29.88%
Weight 0.6%Value $13.06MPrice $18.36Shares 698K -63.36%Since Jun 30 -1.87%
Weight 0.6%Value $11.83MPrice $6.15Shares 1.67MSince Jun 30 -13.38%
Weight 0.5%Value $10.39MPrice $22.44Shares 556KSince Jun 30 +19.94%
Weight 0.5%Value $9.56MPrice $7.91Shares 733KSince Jun 30 -39.39%
Weight 0.4%Value $8.13MPrice $31.73Shares 235KSince Jun 30 -8.24%
Weight 0.3%Value $6.96MPrice $4.00Shares 1.18MSince Jun 30 -32.20%
Weight 0.3%Value $6.78MPrice $7.36Shares 625KSince Jun 30 -32.17%
Weight 0.3%Value $6.55MPrice $23.67Shares 270KSince Jun 30 -2.41%
| Stock | Weight | Value | Since Jun 30 | Shares change | Action |
|---|---|---|---|---|---|
| 29.2% | $600.45M | +4.06% | — | Hold | |
| 25.9% | $531.91M | -25.38% | — | Hold | |
| 7.6% | $155.49M | -38.91% | — | Hold | |
| 5.2% | $106.17M | -0.75% | +35.60% | Add | |
| 3.8% | $78.62M | +63.51% | — | Hold | |
| 3.7% | $75.77M | +2.68% | — | Hold | |
| 3.5% | $72.87M | +23.45% | — | Hold | |
| 3.1% | $63.87M | +78.83% | — | New | |
| 2.4% | $49.98M | -1.53% | — | Hold | |
| 1.9% | $39.98M | -9.73% | — | Hold | |
| 1.2% | $24.05M | -20.90% | +635.00% | Add | |
| 1.2% | $23.97M | +1.09% | — | New | |
| 1.1% | $23.10M | -34.83% | — | New | |
| 1.0% | $21.51M | -48.56% | — | Hold | |
| 1.0% | $21.45M | +4.62% | -50.00% | Trim | |
| 1.0% | $20.04M | +5.44% | — | Hold | |
| 0.9% | $17.82M | -29.88% | +1458.34% | Add | |
| 0.6% | $13.06M | -1.87% | -63.36% | Trim | |
| 0.6% | $11.83M | -13.38% | — | New | |
| 0.5% | $10.39M | +19.94% | — | New | |
| 0.5% | $9.56M | -39.39% | — | Hold | |
| 0.4% | $8.13M | -8.24% | — | New | |
| 0.3% | $6.96M | -32.20% | — | Hold | |
| 0.3% | $6.78M | -32.17% | — | Hold | |
| 0.3% | $6.55M | -2.41% | — | New |
Weight is the share of the reported 13F value, including options at notional value. “Since Jun 30” compares the latest close with the quarter-end price implied by the filing (value ÷ shares).
Largest buys in 2026 Q2
Largest sells in 2026 Q2
Options
Notional value, listed apart from stocks
Source: SEC Form 13F, values as reported by the filer. Filings lag up to 45 days after quarter end and cover only certain long positions. Research only, not investment advice.