EcoR1 Capital, LLC
CIK 1587114 · last filed 2026-05-11
"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.
Charts
Trading activity, where the exposure sits, and each trade against the stock price.
PRTA price and trades
Daily close with each Form 4 filing on this company marked: green = open-market buy, red = open-market sale, purple = grants, exercises, gifts and other non-market transactions. Marker size scales with the dollar value.
Shares held
Shares owned after each reported transaction on this company (direct holdings as reported).
Open-market buying and selling
by monthDollar value of open-market purchases (code P, up) and sales (code S, down) across all companies, by filing month. Grants, exercises and gifts are excluded.
Exposure by company
latestMost recently reported shares × current price. Faded bars (*) have had no filing in 3 years, so the person may no longer hold them. Click a bar to chart that company.
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 | $8.35 | $12.96M | $4.74M | 1 | 2026-05-11 |
| TRAX | 10%+ Owner | 3,174,519 | $43.48 | $138.03M | $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 | $8.40 | $69.44M | -$5.40M | 10 | 2025-05-06 |
| ZYME | Director | 15,720,161 | $28.37 | $445.98M | $81.32M | 13 | 2025-01-21 |
| ANAB | Director | 7,880,094 | $48.77 | $384.31M | $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 | $22.20 | $262.70M | -$8.44M | 1 | 2024-11-08 |
| VYGR | 10%+ Owner | 3,961,507 | $1.75 | $6.93M | -$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 | $10.45 | $21.75M | -$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 · Page 2 of 5
43 filings| Filed | Symbol | Action | Net Shares | Net $ | Link |
|---|---|---|---|---|---|
| 2024-12-27 | ZYME | Buy (P) | +130,309 | $1.88M | EDGAR |
| 2024-12-26 | ZYME | Buy (P) | +1,254,808 | $17.54M | EDGAR |
| 2024-12-23 | Mersana Therapeutics, Inc. (MRSN) Delisted | Other (J) | −8,036,688 | $0 | EDGAR |
| 2024-12-23 | ZYME | Buy (P) | — | $0 | EDGAR |
| 2024-11-08 | TNGX | Sell (S) | −2,700,000 | -$8.44M | EDGAR |
| 2024-08-16 | ANAB | Buy (P) | +273,972 | $10.00M | EDGAR |
| 2023-12-28 | ZYME | Buy (P) | — | $0 | EDGAR |
| 2023-06-21 | ZYME | Buy (P) | +3,350,000 | $27.20M | EDGAR |
| 2023-03-30 | ZYME | Buy (P) | +200,000 | $1.60M | EDGAR |
| 2023-01-23 | ZYME | Buy (P) | +307,500 | $2.98M | 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.