{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-21-344336","form_type":"8-K","ticker":"MKTX","cik":"0001278021","company_name":"MARKETAXESS HOLDINGS INC","filed_at":"2021-12-01T23:59:59+00:00","discovered_at":"2026-05-14T18:04:11.888191+00:00","generated_at":"2026-06-28T04:22:33.787451+00:00","sec_items":["5.02"],"event_type":"leadership","sentiment":"neutral","materiality_score":0.5,"calibrated_materiality_score":0.5,"confidence":"high","headline":"MarketAxess CIO Nick Themelis to retire; new CIO hired, starts March 1, 2022","bullets":["Nick Themelis notified his retirement from MarketAxess on November 24, 2021.","New CIO has been hired, currently on garden leave, and will join on March 1, 2022.","Themelis will remain as CIO until the successor starts, then serve as advisor through February 2023.","Company plans to announce the new CIO's name in the first quarter of 2022."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-21-344336","json":"https://secwatch.observer/filing/0001193125-21-344336.json","markdown":"https://secwatch.observer/filing/0001193125-21-344336.md","text":"https://secwatch.observer/filing/0001193125-21-344336.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1278021/000119312521344336/0001193125-21-344336-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1278021/000119312521344336/d244325d8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-28T04:22:33.787451+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":"bfce53df61","claim":"Nick Themelis departed as Chief Information Officer at MARKETAXESS HOLDINGS INC.","evidence_excerpt":"On November 24, 2021, Nick Themelis notified MarketAxess Holdings Inc. (the “Company”) that he intends to retire from the Company.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1278021/000119312521344336/0001193125-21-344336-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"intends to retire"},{"label":"Role","value":"Chief Information Officer"}],"fact_type":"executive_change"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}