X0306 4 2018-02-13 0 0001539838 Diamondback Energy, Inc. FANG 0001196107 HOLDER RANDALL J 500 WEST TEXAS, SUITE 1200 MIDLAND TX 79701 0 1 0 0 Exec. VP, Gen. Counsel, Sec. Common Stock 2018-02-13 4 A 0 5598 0.00 A 12503 D Common Stock 2018-02-14 4 A 0 12022 0.00 A 24525 D These securities are restricted stock units, each representing a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units were granted under the issuer's equity incentive plan and will vest in three equal annual installments beginning on February 21, 2018. These securities are performance based restricted stock units for the performance period January 1, 2016 to December 31, 2017 that were granted under the issuer's equity incentive plan. All of these performance based restricted stock units vested as of December 31, 2017 upon certification by the issuer's compensation committee of attainment of the applicable performance conditions on February 14, 2018. /s/ Randall J. Holder 2018-02-15