{"schema_version":"secwatch.filing_event.v1","accession":"0001437749-25-004350","form_type":"8-K","ticker":"MRTN","cik":"0000799167","company_name":"MARTEN TRANSPORT LTD","filed_at":"2025-02-19T23:59:59+00:00","discovered_at":"2026-05-14T18:03:06.376573+00:00","generated_at":"2026-05-26T12:46:07.610026+00:00","sec_items":["5.02"],"event_type":"leadership","sentiment":"neutral","materiality_score":0.25,"calibrated_materiality_score":0.25,"confidence":"high","headline":"Director Thomas J. Winkel steps down from Marten Transport board at 2025 Annual Meeting","bullets":["Thomas J. Winkel will not seek reelection at the 2025 Annual Meeting for personal reasons.","He will continue serving on the Board until the Annual Meeting.","Winkel stated his decision is not due to any disagreement with the Company.","No replacement announced; board size will decrease by one after the meeting."],"urls":{"canonical":"https://secwatch.observer/filing/0001437749-25-004350","json":"https://secwatch.observer/filing/0001437749-25-004350.json","markdown":"https://secwatch.observer/filing/0001437749-25-004350.md","text":"https://secwatch.observer/filing/0001437749-25-004350.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/799167/000143774925004350/0001437749-25-004350-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/799167/000143774925004350/mrtn20250218_8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-05-26T12:46:07.610026+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":"ffd4449e8b","claim":"Thomas J. Winkel departed as Director at MARTEN TRANSPORT LTD.","evidence_excerpt":"On February 13, 2025, Mr. Thomas J. Winkel, a member of the Board of Directors of Marten Transport, Ltd. (the “Company”), notified the Company that he will not seek reelection as a director of the Company at the Company’s upcoming 2025 Annual Meeting of Stockholders for personal reasons.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/799167/000143774925004350/0001437749-25-004350-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"will not seek reelection"},{"label":"Role","value":"Director"}],"fact_type":"executive_change"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}