Company facts
- Headquarters
- Thousand Oaks, California
- Most recent report
- 10-Q, filed Aug 12, 2026
- Incorporated
- Delaware
- Filings on record
- 1,002+ filings
- On EDGAR
- CIK 1604464
- Fiscal year ends
- December
- Filer status
- Non-accelerated filer, Smaller reporting company
Financials 8 of 45
News 8 of 139
Prospectuses and Registrations 8 of 47
- S-8 Registration statement for an employee plan Jun 12, 2026
- 424B5 Prospectus supplement for an offering May 12, 2026
- 424B3 Prospectus supplement for an offering Mar 25, 2026
- S-3 Shelf registration statement Mar 17, 2026
- 424B5 Prospectus supplement for an offering Mar 16, 2026
- 424B5 Prospectus supplement for an offering May 15, 2025
- S-8 Registration statement for an employee plan Jan 17, 2025
- 424B5 Prospectus supplement for an offering Sep 4, 2024
Proxies 8 of 27
- DEF 14A Proxy statement for a shareholder vote Apr 24, 2026
- DEFA14A Extra proxy material Apr 24, 2026
- DEFA14A Extra proxy material Apr 28, 2025
- DEF 14A Proxy statement for a shareholder vote Apr 28, 2025
- DEFR14A May 10, 2024
- DEFA14A Extra proxy material Apr 26, 2024
- DEF 14A Proxy statement for a shareholder vote Apr 26, 2024
- PRE 14A Preliminary proxy statement Apr 12, 2024
Ownership 8 of 724
- 4 Insider reported a trade Sep 4, 2026
- 144 Notice of a proposed sale of restricted stock Aug 26, 2026
- 4 Insider reported a trade Aug 26, 2026
- SCHEDULE 13G/A Large holder reported a passive stake, amended Aug 14, 2026
- 4 Insider reported a trade Jul 24, 2026
- SCHEDULE 13D/A Large holder reported an active stake, amended Jul 24, 2026
- 3 Insider reported their initial holding Jul 6, 2026
- 4 Insider reported a trade Jun 15, 2026
Other 8 of 20
- EFFECT Notice that a registration became effective Mar 25, 2026
- CORRESP Reply to SEC staff Mar 23, 2026
- UPLOAD Comment letter from SEC staff Mar 20, 2026
- EFFECT Notice that a registration became effective Nov 13, 2023
- CORRESP Reply to SEC staff Nov 8, 2023
- UPLOAD Comment letter from SEC staff Nov 6, 2023
- UPLOAD Comment letter from SEC staff May 2, 2023
- CORRESP Reply to SEC staff Apr 21, 2023
Everything here comes from Atara Biotherapeutics, Inc.'s own filings on SEC EDGAR. The filing list is rechecked every hour.