EcoR1 Capital, LLC
CIK 1587114 · last filed 2026-05-11
EcoR1 Capital, LLC is a corporate insider who has filed 43 SEC Form 4 insider transactions across 16 companies since 2014. The most recent filing shows the insider bought $4.7M of ATRA on May 11, 2026. Across all open-market trades the lifetime net is +$269.0M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $1.36B across reported positions. The firm reports its address in San Francisco, CA. 28 SEC filings were submitted jointly with OLEG NODELMAN.
"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.
$1.36B
16
43
$269.05M
Filer Profile
SAN FRANCISCO, CA 94103
Holdings By Company
| Symbol | Role | Shares | Price | Disclosed Exposure | Lifetime OM Net | Filings | Latest Filed |
|---|---|---|---|---|---|---|---|
| ATRA | 10%+ Owner | 1,552,000 | $9.38 | $14.56M | $4.74M | 1 | 2026-05-11 |
| TRAX | 10%+ Owner | 3,174,519 | $36.44 | $115.68M | $65.00M | 1 | 2026-04-22 |
| Adaptimmune Therapeutics PLC (ADAP) Delisted | 10%+ Owner | 127,805,220 | $0.06 | $7.40M | -$6.89M | 1 | 2025-07-30 |
| iTeos Therapeutics, Inc. (ITOS) Delisted | 10%+ Owner | 7,388,978 | $10.15 | $75.00M | $38.69M | 1 | 2025-05-16 |
| PRTA | 10%+ Owner | 8,266,342 | $8.93 | $73.82M | -$5.40M | 10 | 2025-05-06 |
| ZYME | Director | 15,720,161 | $26.24 | $412.50M | $81.32M | 13 | 2025-01-21 |
| ANAB | Director | 7,880,094 | $53.87 | $424.50M | $92.83M | 6 | 2025-01-02 |
| Mersana Therapeutics, Inc. (MRSN) Delisted | 10%+ Owner | 453,120 | $29.08 | $13.18M | $0 | 1 | 2024-12-23 |
| TNGX | 10%+ Owner | 11,836,178 | $23.78 | $281.46M | -$8.44M | 1 | 2024-11-08 |
| VYGR | 10%+ Owner | 3,961,507 | $3.19 | $12.64M | -$4.48M | 2 | 2023-01-11 |
| Odonate Therapeutics, Inc. (ODT) Delisted | 10%+ Owner | 545,000 | $1.12 | $610.4K | -$9.43M | 1 | 2021-12-10 |
| CRVS | 10%+ Owner | 2,081,077 | $12.91 | $26.87M | -$25.06M | 1 | 2021-10-01 |
| Surface Oncology, Inc. (SURF) Delisted | 10%+ Owner | 4,701,081 | $1.07 | $5.03M | -$2.38M | 1 | 2020-09-03 |
| Nuvation Bio Inc. (PANA.U) Delisted | Director | 390,000 | — | — | $27.30M | 1 | 2020-07-06 |
| Akouos, Inc. (AKUS) Delisted | 10%+ Owner | 1,975,984 | $13.29 | $26.26M | $19.99M | 1 | 2020-07-02 |
| GENVEC INC (GNVC) Delisted | 10%+ Owner | 111,767 | — | — | $1.25M | 1 | 2014-03-28 |
Recent Filings
43 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2026-05-11 | ATRA | Buy (P) | +507,407 | $4.74M | EDGAR |
| 2026-04-22 | TRAX | Sell (S) | +4,705,575 | $65.00M | EDGAR |
| 2025-07-30 | Adaptimmune Therapeutics PLC (ADAP) Delisted | Sell (S) | −64,052,538 | -$6.89M | EDGAR |
| 2025-05-16 | iTeos Therapeutics, Inc. (ITOS) Delisted | Buy (P) | +4,958,978 | $38.69M | EDGAR |
| 2025-05-06 | PRTA | Sell (S) | −6,279,684 | -$50.84M | EDGAR |
| 2025-01-21 | ZYME | Buy (P) | +141,429 | $1.96M | EDGAR |
| 2025-01-15 | ZYME | Buy (P) | +167,654 | $2.28M | EDGAR |
| 2025-01-10 | ZYME | Buy (P) | +225,119 | $2.97M | EDGAR |
| 2025-01-02 | ANAB | Buy (P) | +170,196 | $2.20M | EDGAR |
| 2025-01-02 | ZYME | Buy (P) | +363,369 | $5.32M | EDGAR |
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.