EcoR1 Capital, LLC
SEC Form 4 insider trading activity
EcoR1 Capital, LLC has filed 3 SEC Form 4 filings (7 transaction rows) across 3 companies, including ATRA, TRAX, AKTS, with disclosures dating back to 2026. 3 of those filings fall inside the rolling window. Most recent filing: May 11, 2026.
On the most recent filing, EcoR1 Capital, LLC is listed as 10% Owner at Atara Biotherapeutics, Inc. Inside the rolling window, EcoR1 Capital, LLC reported 2 open-market purchases totaling $44.7M in ATRA and AKTS and 1 open-market sale totaling $65.0M in TRAX. The largest disclosed transaction in the window is a sale of 4,705,575 TRAX shares on Apr 20, 2026, worth $65.0M.
Companies traded
Other insiders at ATRA
Insider Buying
$44.7M
reported purchases (SEC code P)
Insider Selling
$65.0M
reported sales (SEC code S)
Companies
3
in the rolling window
Frequently asked questions
How many SEC Form 4 filings has EcoR1 Capital, LLC made?
EcoR1 Capital, LLC has filed 3 SEC Form 4 filings (7 transaction rows) across 3 companies, including ATRA, TRAX, AKTS since 2026.
Which companies does EcoR1 Capital, LLC trade?
EcoR1 Capital, LLC has filed SEC Form 4 disclosures for 3 companies, including ATRA, TRAX, AKTS.
When was EcoR1 Capital, LLC's most recent SEC Form 4 filing?
EcoR1 Capital, LLC's most recent SEC Form 4 filing on Tracefour is dated May 11, 2026.
What is EcoR1 Capital, LLC's total buy and sell value in the current window?
Inside the rolling retention window, EcoR1 Capital, LLC bought $44.7M and sold $65.0M based on SEC Form 4 filings.
What was EcoR1 Capital, LLC's largest disclosed transaction?
The largest disclosed transaction in the current window is a sale of 4,705,575 TRAX shares on 2026-04-20, worth $65.0M, per SEC Form 4 filings.