SF: Company disclosure

Item 7.01 Regulation FD Disclosure. On September 24, 2026, Stifel Financial Corp. (the “Company”) issued a press release to disclose selected operating results for August 31, 2026. A copy of the press release is attached as Exhibit 99.1 to this Report on Form 8-K, and is incorporated by reference. The exhibit is being furnished pursuant to Item 2.02, and the information contained therein shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall it be deemed incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Exchange Act. Item 9.01 Financial Statements and Exhibits. (d) Exhibits. Exhibit Number Description 99.1 Press release dated September 24, 2026. 104 Cover Page Interactive Data File (embedded within the Inline XBRL document). 2 SIGNATURE 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. STIFEL FINANCIAL CORP. (Registrant) Date: September 24, 2026 By: /s/ James M. Marischen Name: James M. Marischen Title: Chief Financial Officer 3