X0202 SCHEDULE 13D/A 0001140361-24-041064 0002021141 XXXXXXXX LIVE 7 Common Stock, par value $0.01 per share 09/16/2026 0001539838 25278X109 Diamondback Energy, Inc.

500 WEST TEXAS AVENUE SUITE 100 MIDLAND TX 79701

Hillary H. Holmes (346) 718-6600 Gibson, Dunn & Crutcher LLP 811 Main Street, Suite 3000 Houston TX 77002 Y SGF FANG Holdings, LP a OO DE 0.00 64957047 0.00 64957047 64957047 23.2 PN Note to Row 13: Based upon 280,024,353 shares of Company Common Stock outstanding as of July 31, 2026, as disclosed by the Company in its Form 10-Q filed with the Securities and Exchange Commission (the "SEC") on August 5, 2026. 0002021141 N Greth Lyndal a OO X1 0.00 64957047 0.00 64957047 64957047 23.2 IN Note to Row 13: Based upon 280,024,353 shares of Company Common Stock outstanding as of July 31, 2026, as disclosed by the Company in its Form 10-Q filed with the SEC on August 5, 2026. Common Stock, par value $0.01 per share Diamondback Energy, Inc. 500 WEST TEXAS AVENUE SUITE 100 MIDLAND TX 79701 This Amendment No. 7 amends and supplements the statement on Schedule 13D originally filed with the SEC on September 13, 2024, as amended on September 24, 2024, August 15, 2025, December 2, 2025, February 5, 2026, March 16, 2026, and June 5, 2026 (the "Schedule 13D"), by the Reporting Persons with respect to shares of Company Common Stock. Unless otherwise defined herein, capitalized terms used in this Amendment No. 7 shall have the meanings ascribed to them in the Schedule 13D. Unless amended or supplemented below, the information in the Schedule 13D remains unchanged. Item 4 is hereby amended and supplemented to add the following: On September 16, 2026, SGF FANG sold an aggregate of 9,079,675 shares of Common Stock at a price of $205.26 per share pursuant to Rule 144 under the Securities Act of 1933, as amended (the "September 16, 2026 Sale"). In connection with the September 16, 2026 Sale, SGF FANG is subject to a lock-up period from September 16, 2026 through the date 30 days after September 16, 2026, during which SGF FANG may not sell any shares of Common Stock without the mutual agreement of SGF FANG and Morgan Stanley & Co. LLC. Item 5(a) is hereby amended and restated in full. The information contained on the cover pages and Item 2 to this Schedule 13D is incorporated herein by reference. Item 5(b) is hereby amended and restated in full. The information contained on the cover pages and Item 2 to this Schedule 13D is incorporated herein by reference. Item 5(c) is hereby amended and supplemented to add the information set forth in Item 4 of this Schedule 13D. Item 6 is hereby amended and supplemented to add the information set forth in Item 4 of this Schedule 13D. SGF FANG Holdings, LP /s/ Kevin T. Keen 09/17/2026 Greth Lyndal /s/ Kevin T. Keen 09/17/2026