EcoR1 Capital LLC insider trades

Open-market stock purchases and sales by EcoR1 Capital LLC, 10% Owner at Atara Biotherapeutics, Inc, from SEC Form 4 filings since Mar 26, 2014.

Track record: 84% of 76 scored buys are up 5% or more since purchase, averaging +95%.

Recent trades

DateStockTradeValue
May 7, 2026ATRA Atara Biotherapeutics, IncBought$4.7M
Apr 20, 2026TRAX First Tracks Biotherapeutics, IncSold$65M
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought$37.4M
Jan 12, 2026AKTS Aktis Oncology, IncBought$2.6M
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—
Jan 12, 2026AKTS Aktis Oncology, IncBought (not open market)—

Companies traded

  • ATRA Atara Biotherapeutics, Inc: 1 buy, last May 7, 2026
  • TRAX First Tracks Biotherapeutics, Inc: 1 sale, last Apr 20, 2026
  • AKTS Aktis Oncology, Inc: 2 buys, last Jan 12, 2026
  • ADAP Adaptimmune Therapeutics plc: 3 sales, last Jul 30, 2025
  • ZYME Zymeworks Inc: 47 buys, last Jun 26, 2025
  • ITOS iTeos Therapeutics, Inc: 2 buys, last May 15, 2025
  • PRTA Prothena Corp Public Ltd Co: 13 buys, 4 sales, last May 6, 2025
  • ANAB Anaptysbio, Inc: 14 buys, 1 sale, last Jan 2, 2025
  • MRSN Mersana Therapeutics, Inc: other filings, last Dec 19, 2024
  • TNGX Tango Therapeutics, Inc: 3 sales, last Nov 7, 2024
  • VYGR Voyager Therapeutics, Inc: 2 buys, 3 sales, last Jan 11, 2023
  • ODT Odonate Therapeutics, Inc: 1 buy, 4 sales, last Dec 10, 2021

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