Atara Biotherapeutics (ATRA)10% owner bought ~$670K

~$670K

Approx. value · 55K sh @ $12.19

1.41M

Holds after · shares reported

Traded

Aug 15, 2025

Filed

Aug 20, 2025

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. Jul 17, 2025Insider10% owner purchased ~$186K of ATRA shares in the open market
2. Aug 15, 2025 · this disclosureInsider10% owner purchased ~$670K of ATRA shares in the open market

What came next

1. Aug 18, 2025Insider · 2 peopleInsiders: 6 sales (~$55K)
2. Oct 6, 2025Company filing · Form 8-K · RestructuringAnnounced job cuts, closures or a restructuring“On October 6, 2025, Atara Biotherapeutics, Inc. (the “Company”) announced a reduction in its workforce that will impact approximately 29% of its current employees, retaining approximately 15 employees essential to executing on the Company’s strategic priorities.”
3. Nov 12, 2025Company filing · Form 8-K · ResultsReported its results
4. Nov 17, 2025Insider · 2 peopleInsiders: 5 sales (~$62K)

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)May 11, 2026
• SEC Form 4 at Atara Biotherapeutics (ATRA)Jan 15, 2026
• 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 4May 11, 2026

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