EcoR1 Capital
EcoR1 Capital reported 31 stocks worth $2B in its 13F filing for Q2 2026, filed Aug 14, 2026. Its largest holdings are ZYME (29.8%), ANAB (26.4%) and AKTS (7.7%). Compared with Q1 2026, the fund opened new positions in TRAX, FULC and LEGN, added to CGON, STOK and ATRA, trimmed MBX, RLAY and ERAS and sold out of JAZZ, XNCR and REPL.
Holdings
| # | Stock | Value | Weight | Shares | Change | Shares, 8 qtrs | Held |
|---|---|---|---|---|---|---|---|
| 1 |  ZYME Zymeworks Inc | $600M | 29.8% | 23M | No change | 8 of 8 | |
| 2 |  ANAB Anaptysbio Inc | $532M | 26.4% | 7.9M | No change | 8 of 8 | |
| 3 |  AKTS Aktis Oncology Inc | $155M | 7.7% | 4.8M | No change | 2 of 8 | |
| 4 |  CGON CG Oncology Inc | $106M | 5.3% | 1.5M | +392K (+36%) | 3 of 8 | |
| 5 |  ETON Eton Pharmaceuticals Inc | $78.6M | 3.9% | 2.2M | No change | 8 of 8 | |
| 6 |  CRSP Crispr Therapeutics | $75.8M | 3.8% | 1.4M | No change | 8 of 8 | |
| 7 |  ORIC Oric Pharmaceuticals Inc | $72.9M | 3.6% | 6.7M | No change | 8 of 8 | |
| 8 |  TRAX First Tracks Biotherapeutics | $63.9M | 3.2% | 3.2M | New position | 1 of 8 | |
| 9 |  LKFT Galapagos NV | $50M | 2.5% | 1.7M | No change | 8 of 8 | |
| 10 |  NGNE Neurogene Inc | $40M | 2.0% | 1.3M | No change | 8 of 8 |
Positions at Jun 30, 2026, as reported. Change is against the fund's Q1 2026 filing; weight is the share of the fund's reported stocks.
Sold out
held in Q1 2026, gone in Q2 2026| Stock | Value last quarter | Shares sold |
|---|---|---|
 JAZZ Jazz Pharmaceuticals PLC | $323M | 1.7M |
CENTESSA PHARMACEUTICALS PLC | $238M | 6M |
CRINETICS PHARMACEUTICALS IN | $156M | 4.3M |
 XNCR Xencor Inc | $26.3M | 2.2M |
 REPL Replimune Group Inc | $7.7M | 1M |
🔒 Free account: see all 7.
Options
valued at the underlying shares
Reported value
last 8 quartersThe value of the US stocks the fund reported, at quarter end prices. It moves with the market as well as with buying and selling.
Filings for Q2 2026
straight from the SEC| Filed | Form | Quarter | |
|---|---|---|---|
| Aug 14, 2026 | 13F-HR | Q2 2026 | SEC filing ↗ |
Other superinvestors
All hedge fund holdings →EcoR1 Capital 13F FAQ
What does EcoR1 Capital own?
EcoR1 Capital reported 31 stocks worth $2B in its 13F filing for Q2 2026, filed Aug 14, 2026. Its largest holdings are ZYME (29.8%), ANAB (26.4%) and AKTS (7.7%). The table above lists every position in the filing (the top 10 without an account).
What did EcoR1 Capital buy and sell in Q2 2026?
Compared with Q1 2026: 9 new positions, 3 added to, 4 trimmed and 7 sold out. New positions include TRAX, FULC and LEGN. It sold all of JAZZ, XNCR and REPL.
When will EcoR1 Capital file its next 13F?
Holdings as of Sep 30, 2026 are due by Nov 16, 2026. The filing appears on this page within minutes of reaching the SEC.
How much is EcoR1 Capital's portfolio worth?
The Q2 2026 filing reports $2B in US stocks ($2.1B including options). That leaves out cash, bonds, short positions and most foreign holdings, so the fund's total assets are usually larger.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Holdings come from the fund's SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. The fund may have changed its positions since. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.