VST: Material agreement · Other company developments

Item 1.01. Entry into a Material Definitive Agreement. On September 24, 2026, Vistra Operations Company LLC (“Vistra Operations”), an indirect, wholly owned subsidiary of Vistra Corp. (“Vistra”), completed its underwritten public offering of $850,000,000 aggregate principal amount of its 7.000% Series A Junior Subordinated Notes due 2057 (the “Series A Notes”) and $650,000,000 aggregate principal amount of its 7.250% Series B Junior Subordinated Notes due 2057 (the “Series B Notes” and, together with the Series A Notes, the “Notes”), in each case irrevocably and unconditionally guaranteed by Vistra (the “Guarantee” and, together with the Notes, the “Securities”). The Securities were issued pursuant to the Indenture, dated as of September 24, 2026 (the “Base Indenture”), among Vistra Operations, as issuer, Vistra, as guarantor, and Wilmington Trust, National Association, as trustee (the “Trustee”), as supplemented by the First Supplemental Indenture, dated as of September 24, 2026 (together with the Base Indenture, the “Indenture”), among Vistra Operations, Vistra and the Trustee. The Indenture and the terms of the Securities are further described under “Description of the Notes” in the prospectus supplement of Vistra Operations and Vistra dated September 10, 2026, together with the related prospectus dated September 8, 2026, as filed with the Securities and Exchange Commission under Rule 424(b)(2) of the Securities Act of 1933 on September 14, 2026, which descriptions are incorporated herein by reference. The sale of the Securities was registered under Vistra’s and Vistra Operations’ registration statement on Form S-3 filed on September 8, 2026 (File Nos. 333-298811 and 333-298811-01) (the “Registration Statement”). Copies of the Base Indenture, the First Supplemental I