X0508 4 2026-02-20 0001022671 STEEL DYNAMICS INC STLD 0001195950 TEETS RICHARD P JR 7575 W. JEFFERSON BLVD. FORT WAYNE IN 46804 1 0 0 0 0 Common Stock 2026-02-20 4 A 0 197 0 A 4980085 D Common Stock 93119 I By spouse Common Stock 73000 I By Teets Family Foundation Issued as deferred stock units (DSUs) in connection with reporting person's retainer, as a director, under the Company's 2023 Equity Incentive Plan and exempt from Section 16(b) by virtue of Rule 16b-3(d)(1) and (3). These DSUs are reportable, however, as directly owned shares of common stock, rather than as derivative security in Table II, because any and all underlying DSUs are payable, at such time as they are to be settled, solely in common stock. (See Lincoln National Corp. (March 20, 1992) (Q.3) Represents securities held by the Teets Family Foundation, a charitable foundation of which the reporting person is a member and director. The reporting person has voting and investment power over all securities owned by the foundation. /s/ Richard P. Teets, Jr. 2026-02-23