---
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"
generated_at: "2026-06-08T03:45:29.274368+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.35
calibrated_materiality_score: 0.35
confidence: "high"
source: SEC EDGAR
---

# Vistra appoints Margaret Montemayor as SVP, Chief Accounting Officer and Controller

## Summary
- 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.

## SEC filing metadata
- 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
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.35
- calibrated_materiality_score: 0.35
- confidence: high
- sec_items: 5.02, 9.01
- 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

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-276580
- JSON: https://secwatch.observer/filing/0001193125-23-276580.json
- Plain text: https://secwatch.observer/filing/0001193125-23-276580.txt

## Key facts
- Executive change
  Margaret Montemayor was appointed as Senior Vice President, Chief Accounting Officer and Controller at Vistra Corp..
  - Action: appointed
  - Role: Senior Vice President, Chief Accounting Officer and Controller
  source text: 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_url: https://www.sec.gov/Archives/edgar/data/1692819/000119312523276580/0001193125-23-276580-index.htm
- Executive change
  Christy Dobry changed role as former Senior Vice President and Controller at Vistra Corp..
  - Action: assume another role
  - Role: former Senior Vice President and Controller
  source text: 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_url: https://www.sec.gov/Archives/edgar/data/1692819/000119312523276580/0001193125-23-276580-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.