Item 1.01. Entry Into or Amendment of a Material Definitive Agreement. Convertible Notes

Item 2.03. Creation of a Direct Financial Obligation or an Off-Balance Sheet Arrangement. The disclosure set forth in Item 1.01 above under the caption “ Convertible Notes - Indenture” is incorporated by reference into this Item 2.03.

Item 3.02 Unregistered Sales of Equity Securities The disclosure set forth in Item 1.01 above under the caption “ Convertible Notes - Indenture” is incorporated by reference into this Item 3.02. The shares of Class A common stock issuable upon conversion of the Notes have not been registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. We do not intend to file a registration statement for the resale of the Notes or any shares of Class A common stock issuable upon conversion of the Notes. We anticipate any such future issuances will be made in accordance with Section 3(a)(9) under the Securities Act.

Item 9.01. Financial Statements and Exhibits. (d)  Exhibits Exhibit Description No. 1.1 # Underwriting Agreement, dated as of October 6, 2025, by and between Solaris Energy Infrastructure, Inc. and Morgan Stanley & Co. LLC, as representative of the underwriters named therein (Notes Offering). 1.2 # Underwriting Agreement, dated as of October 6, 2025, by and between Solaris Energy Infrastructure, Inc. and Morgan Stanley & Co. LLC, as underwriter (Concurrent Delta Offering). 4.2 Second Supplemental Indenture, dated as of October 8, 2025, between Solaris Energy Infrastructure, Inc. and U. S. Bank Trust Company, National Association, as trustee. ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 4.1 Indenture, dated May 2, 2025, by and between Solaris Energy Infrastructure, Inc. and U. S. Bank Trust Company, National Association, as Trustee (incorporated by reference to Exhibit 4.1 to the Registrant’s Form 8-K (File No. 001-38090) filed with the U. S. Securities and Exchange Commission on May 2, 2025). 4.3 Form of 0.25% Convertible Senior Note Due 2031 (included as Exhibit A to Exhibit 4.2). 5.1 Opinion of Vinson & Elkins L. L. P. (Notes Offering). 5.2 Opinion of Vinson & Elkins L. L. P. (Concurrent Delta Offering). 10.1 Form of Capped Call Confirmation 23.1 Consent of Vinson & Elkins L. L. P. (Notes Offering) (included in Exhibit 5.1). 23.2 Consent of Vinson & Elkins L. L. P. (Concurrent Delta Offering) (included in Exhibit 5.2). 104 Cover Page Interactive Data File (embedded within Inline XBRL document). Certain annexes, schedules and exhibits have been omitted pursuant to Item 601(a)(5) of Regulation S-K. The Corporation agrees to furnish supplementally an unredacted copy of the exhibit to the Securities and Exchange Commission upon its request. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. SOLARIS ENERGY INFRASTRUCTURE, INC. By: /s/ Kyle S. Ramachandran Name: Kyle S. Ramachandran Title: President and Chief Financial Officer