{"schema_version":"secwatch.filing_event.v1","accession":"0001193125-23-276580","form_type":"8-K","ticker":"VST","cik":"0001692819","company_name":"Vistra Corp.","filed_at":"2023-11-14T23:59:59+00:00","discovered_at":"2026-05-14T18:03:30.080683+00:00","generated_at":"2026-06-08T03:45:29.274368+00:00","sec_items":["5.02","9.01"],"event_type":"leadership","sentiment":"neutral","materiality_score":0.35,"calibrated_materiality_score":0.35,"confidence":"high","headline":"Vistra appoints Margaret Montemayor as SVP, Chief Accounting Officer and Controller","bullets":["Montemayor, 46, most recently VP and Chief Accounting Officer at Pioneer Natural Resources (2014-2022).","Appointment effective November 13, 2023; succeeds Christy Dobry who moves to another internal role.","No family relationships or material transactions with officers; no compensatory plan changes disclosed.","Montemayor is a CPA with a BBA in Accounting and MBA from St. Mary's University."],"urls":{"canonical":"https://secwatch.observer/filing/0001193125-23-276580","json":"https://secwatch.observer/filing/0001193125-23-276580.json","markdown":"https://secwatch.observer/filing/0001193125-23-276580.md","text":"https://secwatch.observer/filing/0001193125-23-276580.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/1692819/000119312523276580/0001193125-23-276580-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/1692819/000119312523276580/d314544d8k.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-08T03:45:29.274368+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":"9b20c990a6","claim":"Margaret Montemayor was appointed as Senior Vice President, Chief Accounting Officer and Controller at Vistra Corp..","evidence_excerpt":"On November 10, 2023, the board of directors (the “ Board ”) of Vistra Corp. (the “ Company ”) approved the appointment of Margaret Montemayor as Senior Vice President, Chief Accounting Officer and Controller of the Company, effective November 13, 2023.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1692819/000119312523276580/0001193125-23-276580-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"appointed"},{"label":"Role","value":"Senior Vice President, Chief Accounting Officer and Controller"}],"fact_type":"executive_change"},{"claim_id":"a73e679d3c","claim":"Christy Dobry changed role as former Senior Vice President and Controller at Vistra Corp..","evidence_excerpt":"Ms. Montemayor will succeed the Company’s former Senior Vice President and Controller, Christy Dobry, who will assume another role within the Company effective November 13, 2023.","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1692819/000119312523276580/0001193125-23-276580-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"assume another role"},{"label":"Role","value":"former Senior Vice President and Controller"}],"fact_type":"executive_change"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}