VST: Material agreement · New financial obligation

Item 1.01. Entry into Material Definitive Agreements. On June 24, 2026, Vistra Operations Company LLC (“Vistra Operations”) (as Borrower), an indirect, wholly owned subsidiary of Vistra Corp. (the “Company”), entered into (a) an amendment (the “Credit Agreement Amendment”) among Vistra Operations, the lenders party thereto, the letter of credit issuers party thereto, the cash management bank party thereto, Citibank, N.A., as Administrative and Collateral Agent, and the other parties named therein, which amended that certain Credit Agreement, dated as of October 3, 2016 (as amended, supplemented or otherwise modified from time to time, including by the Credit Agreement Amendment, the “Credit Agreement”) and (b) an amendment (the “Commodity-Linked Credit Agreement Amendment”) among Vistra Operations, the lenders party thereto and Citibank, N.A., as Administrative and Collateral Agent, which amended that certain Credit Agreement, dated as of February 4, 2022 (as amended, supplemented or otherwise modified from time to time, including by the Commodity-Linked Credit Agreement Amendment, the “Commodity-Linked Credit Agreement”). Capitalized terms used but not defined herein have the meanings given to such terms in the Credit Agreement Amendment, the Credit Agreement, the Commodity-Linked Credit Agreement Amendment or the Commodity-Linked Credit Agreement, as applicable. Pursuant to the Credit Agreement Amendment, effective as of June 24, 2026, the Credit Agreement was amended to, among other things, (a) increase the aggregate revolving credit commitments from $3.44 billion to $5.50 billion, (b) release each guarantor from its guarantee to the extent related to the revolving credit loans, revolving credit commitments, letters of credit, letter of credit commitments and/or secu