X0609 4 2026-03-18 0 0001539838 Diamondback Energy, Inc. FANG 0001190898 WEST STEVEN E 500 WEST TEXAS AVENUE SUITE 100 MIDLAND TX 79701 1 0 0 0 0 Common Stock 2026-03-18 4 S 0 6000 188.3548 D 4484 D The price reported in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $187.95 per share to $188.69 per share, inclusive. The reporting person undertakes to provide to Diamondback Energy, Inc., any security holder of Diamondback Energy, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. Reflects the transfer of 3,068 shares of Common Stock in a transfer exempt from reporting pursuant to Rule 16a-12. /s/ Matt Zmigrosky, as attorney-in-fact for Steven E. West 2026-03-19