STLD: Other company developments

Item 8.01. Other Events. On October 19, 2026, Steel Dynamics, Inc. issued a press release titled “Steel Dynamics Announces Leadership Promotions.” A copy of that press release is attached hereto as Exhibit 99.1 and incorporated herein by reference. Item 9.01. Financial Statements and Exhibits (d) Exhibits. The following exhibit is filed with this report: Exhibit Number Description 99.1 A press release dated October 19, 2026, titled “Steel Dynamics Announces Leadership Promotions.” 104 Cover Page Interactive Data File – the cover page interactive data file does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document. 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 hereto duly authorized. STEEL DYNAMICS, INC. /s/ Theresa E. Wagler Date: October 19, 2026 By: Theresa E. Wagler Title: Executive Vice President and Chief Financial Officer