Atara Biotherapeutics (ATRA)10% owner sold ~$3.17M

~$3.17M

Approx. value · 313K sh @ $10.10

1.01M

Holds after · shares reported

Traded

May 7, 2026

Filed

May 11, 2026

The story around this disclosure

Every dated public record OQRO holds about the company from 60 days before to 120 days after, oldest first. It shows what was going on; none of it is a stated reason for the trade.

1. Mar 16, 2026Company filing · Form 8-K · ResultsReported its results
2. Apr 30, 2026Company filing · Form 8-K · Listing noticeReceived a notice from its stock exchange“On April 30, 2026, Atara Biotherapeutics, Inc. (the “Company”) received a notice (the “Notice”) from the Listing Qualifications Department (the “Staff”) of The Nasdaq Stock Market LLC (“Nasdaq”) notifying the Company that the Company no longer meets Nasdaq’s $50 million minimum market value for listed securities (“MVLS”) requirement pursuant to Nasdaq Listing Rule 5450(b)(2)(A) (the “MVLS Requirement”) for continued…”
3. May 7, 2026 · this disclosureInsider10% owner sold ~$3.17M of ATRA shares in the open market

What came next

1. May 7, 2026Insider · Largest insider buy since 201410% owner purchased ~$4.74M of ATRA shares in the open market
2. May 18, 2026Insider · 2 peopleInsiders: 2 sales (~$70K)
3. Jun 9, 2026Company filing · Form 8-K · Executive change, Shareholder voteChanged a top executive or board member, and held a shareholder vote“On June 11, 2026, the Board of Directors (the “ Board ”) of Atara Biotherapeutics, Inc. (the “ Company ”) appointed Brian Cherry to serve as a member of the Board as a Class I director, effective June 11, 2026 (the “ Effective Date ”).”
4. Jun 22, 2026Company filing · Form 8-K · Executive changeChanged a top executive or board member“On June 22, 2026, Atara Biotherapeutics, Inc. (the “Company”) notified Yanina Grant-Huerta, the Company’s Chief Accounting Officer, that her employment with the Company would end effective July 17, 2026.”
5. Aug 12, 2026Company filing · Form 8-K · ResultsReported its results
6. Aug 17, 2026InsiderCEO sold ~$41K of ATRA shares in the open market
7. Sep 4, 2026Insider · Their first buy on recordDirector purchased ~$1M of ATRA shares in the open market

How to read SEC Form 4

Form 4 is the filing that officers, directors and owners of more than 10% of a US-listed company must send to the SEC within two business days after they buy, sell or otherwise change their holding of the company's stock.

Full guide: What is an SEC Form 4?

What else is on file for Atara Biotherapeutics

For Atara Biotherapeutics, OQRO holds 2 insider filings (SEC Form 4 or Form 144) dated in the last 90 days.

These are records OQRO holds, counted by their date, not a measure of how much trading took place. Routine paperwork such as option exercises and tax withholding is left out. Everything for the company is on its ATRA page.

Other recent filings by Panacea Innovation Ltd, 10% owner

• SEC Form 4 at Atara Biotherapeutics (ATRA)Jan 15, 2026
• SEC Form 4 at Atara Biotherapeutics (ATRA)Aug 20, 2025
• SEC Form 4 at Atara Biotherapeutics (ATRA)Jul 21, 2025

The full history of Panacea Innovation Ltd, 10% owner is on the profile page.

How this filing works

• SEC Form 4
• Open-market purchase
• Rule 10b5-1 trading plans

Other disclosures at Atara Biotherapeutics

• SEC Form 4Sep 4, 2026
• SEC Form 4Aug 26, 2026
• SEC Form 4May 20, 2026
• SEC Form 4May 20, 2026
• SEC Form 4May 11, 2026
• SEC Form 4Mar 4, 2026

Everything OQRO holds on this company is on its ATRA page.