{"schema_version":"secwatch.filing_event.v1","accession":"0000950170-23-011416","form_type":"8-K","ticker":"ATRA","cik":"0001604464","company_name":"Atara Biotherapeutics, Inc.","filed_at":"2023-03-31T23:59:59+00:00","discovered_at":"2026-05-14T18:03:45.799814+00:00","generated_at":"2026-06-17T07:55:01.714625+00:00","sec_items":["5.02"],"event_type":"leadership","sentiment":"negative","materiality_score":0.65,"calibrated_materiality_score":0.65,"confidence":"high","headline":"Atara CFO Utpal Koppikar resigns effective March 31; enters six-month consulting agreement","bullets":["Utpal Koppikar resigned as CFO effective March 31, 2023, and entered a six-month consulting agreement.","Consulting fee: $2,800/month for up to a specified number of hours, plus $175/hour for excess hours.","Outstanding equity awards will continue to vest during the consulting term.","No successor named in the filing; search for new CFO is presumably ongoing."],"urls":{"canonical":"https://secwatch.observer/filing/0000950170-23-011416","json":"https://secwatch.observer/filing/0000950170-23-011416.json","markdown":"https://secwatch.observer/filing/0000950170-23-011416.md","text":"https://secwatch.observer/filing/0000950170-23-011416.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023011416/0000950170-23-011416-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023011416/atra-20230331.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-17T07:55:01.714625+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[{"claim_id":"0a18174f3e","claim":"Utpal Koppikar resigned as Executive Vice President, Chief Financial Officer at Atara Biotherapeutics, Inc..","evidence_excerpt":"On February 3, 2023, Atara Biotherapeutics, Inc., a Delaware corporation (the “Company”), announced that Utpal Koppikar, the Company’s Executive Vice President, Chief Financial Officer, notified the Company of his intention to resign from the Company effective as of March 31, 2023.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1604464/000095017023011416/0000950170-23-011416-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"resigned"},{"label":"Role","value":"Executive Vice President, Chief Financial Officer"}],"fact_type":"executive_change"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}