EcoR1 Capital, LLC
Q4 2025 13F-HR Holdings
Net value change ($000)
+120,140
(5.8%)
New positions
9
Sold out positions
11
Turnover %
29.6%
Sector allocation + QoQ delta (equities-only)
Snapshot: Change Analysis
Compared to Q3 2025
Methodology:
sector metrics are equities-only;
instrument mix chart is ex-options;
options exposure is shown separately.
Why this matters.
Top Adds (Value $000, Stocks/ETFs)
| ZYME | 212,476 | 54.2% |
| ANAB | 140,739 | 58.3% |
| JAZZ | 65,187 | 29.0% |
| CNTA | 64,568 | 484.1% |
| CGON | 32,053 | NEW |
| MBX | 29,815 | 80.2% |
| ZBIO | 28,667 | NEW |
| GPCR | 23,256 | NEW |
| CRNX | 21,012 | 11.8% |
| PCVX | 20,763 | NEW |
Top Reduces (Value $000, Stocks/ETFs)
| QURE | -232,836 | -100.0% |
| TNGX | -89,298 | -100.0% |
| APLS | -78,009 | -100.0% |
| MDGL | -34,400 | -100.0% |
| RNAM | -33,331 | -100.0% |
| ORIC | -25,701 | -31.8% |
| XNCR | -22,303 | -30.9% |
| CRSP | -17,185 | -19.1% |
| ALKERMES PLC | -15,000 | -100.0% |
| Metsera, Inc. | -14,209 | -100.0% |
Instrument mix + QoQ Δ (ex-options)
Derivatives reported exposure ($000):
13,190
(0.6% of total reported value)
How this table is calculated:
SEC
VALUE ($000) is used as reported.
For derivatives (PUT/CALL/WARRANT/RIGHT), SEC value represents reported underlying exposure, not premium cash paid/received.
Column % is bucket-based:
non-options share is calculated inside non-option total, options share is calculated inside options total.
Details.
Filter:
Instrument:
| Issuer Name | Ticker | Sector | Industry | Class | History | Value ($000) | % | Shares | Shares Δ | Shares Δ% | Value Δ ($000) | Value Δ% | Principal | Option Type |
|---|