Trade Summary

6 days ago, Ecor1 Capital, LLC, serving as 10% owner at Atara Biotherapeutics, Inc. (ATRA), purchased 507,407 shares at $9.35 per share, for a total transaction value of $4,744,255.00. Following this transaction, Ecor1 Capital, LLC now holds 1,552,000 shares of ATRA.

This purchase represents a 49.00% increase in Ecor1 Capital, LLC's stake in the company. This is considered a high-conviction trade given the significant change in ownership.

The trade was executed on Thursday, May 7, 2026 and publicly disclosed via SEC Form 4 filing on Monday, May 11, 2026, 4 days after the trade was made.

Atara Biotherapeutics, Inc. operates in the HEALTHCARE sector, specifically within the BIOTECHNOLOGY industry. Insider buying activity in this sector can provide valuable signals about industry trends and company-specific developments.