EcoR1 Capital, LLC

Atara Biotherapeutics, Inc. · 10% Owner

EcoR1 Capital, LLC is listed in public filings as 10 percent owner. This EcoR1 Capital, LLC insider trading page organizes Form 4 disclosures, reported purchases and sales, transaction dates, share amounts, related issuers, and historical insider activity so readers can review the person's public trading record in one place. Companies and tickers connected to this insider trading profile include Atara Biotherapeutics, Inc. (ATRA), Adaptimmune Therapeutics plc (ADAPY), Zymeworks Inc. (ZYME), iTeos Therapeutics, Inc. (ITOS), and Prothena Corporation plc (PRTA). Investors use EcoR1 Capital, LLC's insider trading disclosures to study buying and selling patterns, position changes, company-specific activity, and the source evidence behind each reported transaction.

Latest Actions

CompanyHolding ValueLast TransactionAmountCurrent Price
Atara Biotherapeutics, Inc.ATRA$15M1.6M sharesBuyMay 7, 2026$4.7M507.4k shares$9.35--

Insider Trades History

CompanyHolding ValueLast TransactionAmountTransaction PriceCurrent Price
Adaptimmune Therapeutics plcADAPY$10M100.4M sharesSellJul 30, 2025$2.8M27.4M shares$0.1021--
Adaptimmune Therapeutics plcADAPY$13M127.8M sharesSellJul 29, 2025$272.0K2.7M shares$0.1012--
Adaptimmune Therapeutics plcADAPY$15M130.5M sharesSellJul 28, 2025$3.8M33.9M shares$0.1125--
Zymeworks Inc.ZYME$292M23M sharesGrant / ExerciseJun 26, 2025$52141 shares$12.71--
Zymeworks Inc.ZYME$05.1M sharesOtherJun 26, 2025$5095.1M shares$0.0001--
Zymeworks Inc.ZYME$2.3k23M sharesOtherJun 26, 2025$5095.1M shares$0.0001--
Zymeworks Inc.ZYME$211M17.9M sharesBuyMay 19, 2025$69.7K5.9k shares$11.78--
iTeos Therapeutics, Inc.ITOS$86M10.7M sharesBuyMay 15, 2025$26.4M3.3M shares$8.00--
Zymeworks Inc.ZYME$204M17.9M sharesBuyMay 15, 2025$565.8K49.5k shares$11.43--
iTeos Therapeutics, Inc.ITOS$55M7.4M sharesBuyMay 14, 2025$12.3M1.7M shares$7.41--
Prothena Corporation plcPRTA$41M5.3M sharesSellMay 6, 2025$15.2M2M shares$7.64--
Prothena Corporation plcPRTA$59M7.3M sharesSellMay 5, 2025$7.9M977.7k shares$8.11--
Prothena Corporation plcPRTA$69M8.3M sharesSellMay 2, 2025$27.7M3.3M shares$8.36--
Zymeworks Inc.ZYME$205M17.8M sharesBuyApr 17, 2025$630.8K54.8k shares$11.52--
Zymeworks Inc.ZYME$198M17.8M sharesBuyApr 16, 2025$825.6K74k shares$11.16--
Zymeworks Inc.ZYME$198M17.7M sharesBuyApr 4, 2025$2.2M196.4k shares$11.17--
Zymeworks Inc.ZYME$207M17.5M sharesBuyApr 3, 2025$1.4M120.8k shares$11.84--
Zymeworks Inc.ZYME$206M17.4M sharesBuyApr 2, 2025$881.0K74.4k shares$11.85--
Zymeworks Inc.ZYME$201M17.3M sharesBuyApr 1, 2025$564.6K48.7k shares$11.60--
Zymeworks Inc.ZYME$203M17.3M sharesBuyMar 31, 2025$51.7K4.4k shares$11.75--
Zymeworks Inc.ZYME$211M17.3M sharesBuyMar 26, 2025$536.9K43.8k shares$12.24--
Zymeworks Inc.ZYME$222M17.2M sharesBuyMar 25, 2025$690.5K53.5k shares$12.91--
Zymeworks Inc.ZYME$224M17.2M sharesBuyMar 24, 2025$296.8K22.7k shares$13.08--
Zymeworks Inc.ZYME$219M17.1M sharesBuyMar 21, 2025$396.5K31k shares$12.78--
Zymeworks Inc.ZYME$221M17.1M sharesBuyMar 20, 2025$949.9K73.5k shares$12.93--
Zymeworks Inc.ZYME$215M17M sharesBuyMar 19, 2025$737.2K58.3k shares$12.64--
Zymeworks Inc.ZYME$215M17M sharesBuyMar 18, 2025$1.4M113.9k shares$12.65--
Zymeworks Inc.ZYME$206M16.9M sharesBuyMar 17, 2025$688.5K56.3k shares$12.23--
Zymeworks Inc.ZYME$210M16.8M sharesBuyMar 13, 2025$5.8M468.4k shares$12.48--
Zymeworks Inc.ZYME$200M16.3M sharesBuyMar 12, 2025$3.6M292.9k shares$12.25--
Zymeworks Inc.ZYME$184M16M sharesBuyMar 11, 2025$3.7M320.7k shares$11.49--
Zymeworks Inc.ZYME$218M15.7M sharesBuyJan 17, 2025$274.0K19.7k shares$13.87--
Zymeworks Inc.ZYME$218M15.7M sharesBuyJan 16, 2025$1.7M121.7k shares$13.89--
Zymeworks Inc.ZYME$218M15.6M sharesBuyJan 15, 2025$546.7K39k shares$14.01--
Zymeworks Inc.ZYME$211M15.5M sharesBuyJan 14, 2025$739.3K54.5k shares$13.56--
Zymeworks Inc.ZYME$207M15.5M sharesBuyJan 13, 2025$992.9K74.1k shares$13.39--
Zymeworks Inc.ZYME$202M15.4M sharesBuyJan 10, 2025$2.7M204.1k shares$13.13--
Zymeworks Inc.ZYME$214M15.2M sharesBuyJan 8, 2025$295.8K21k shares$14.07--
Zymeworks Inc.ZYME$224M15.2M sharesBuyJan 2, 2025$2.3M157.9k shares$14.78--
AnaptysBio, Inc.ANAB$102M7.9M sharesBuyJan 2, 2025$86.1K6.6k shares$12.95--
Zymeworks Inc.ZYME$219M15M sharesBuyDec 31, 2024$2.1M146.5k shares$14.57--
AnaptysBio, Inc.ANAB$102M7.9M sharesBuyDec 31, 2024$171.5K13.3k shares$12.93--
Zymeworks Inc.ZYME$215M14.9M sharesBuyDec 30, 2024$853.3K59k shares$14.47--
AnaptysBio, Inc.ANAB$102M7.9M sharesBuyDec 30, 2024$842.1K65.2k shares$12.92--
Zymeworks Inc.ZYME$215M14.8M sharesBuyDec 27, 2024$1.5M101.7k shares$14.49--
Zymeworks Inc.ZYME$212M14.7M sharesBuyDec 26, 2024$240.0K16.7k shares$14.38--
Zymeworks Inc.ZYME$208M14.7M sharesBuyDec 24, 2024$168.9K12k shares$14.12--
Zymeworks Inc.ZYME$209M14.7M sharesBuyDec 23, 2024$3.6M251.5k shares$14.25--
Zymeworks Inc.ZYME$203M14.4M sharesBuyDec 20, 2024$9.9M704.5k shares$14.08--
Zymeworks Inc.ZYME$186M13.7M sharesBuyDec 19, 2024$4.0M298.8k shares$13.53--
Tango Therapeutics, Inc.TNGX$31M10.6M sharesSellNov 7, 2024$3.3M1.1M shares$2.92--
Tango Therapeutics, Inc.TNGX$39M11.8M sharesSellNov 7, 2024$205.1K62.3k shares$3.29--
Tango Therapeutics, Inc.TNGX$39M11.8M sharesSellNov 6, 2024$4.9M1.5M shares$3.28--
AnaptysBio, Inc.ANAB$285M7.8M sharesBuyAug 14, 2024$10.0M274k shares$36.50--
EcoR1 Capital, LLC | TradingNote