Wexford Capital SC 13D Diamondback Energy / WEXFORD CAPITAL ownership change

EXHIBIT 99.1

JOINT FILING AGREEMENT

Pursuant to Rule 13d-1(k)(1)(iii) of the Securities Exchange Act of 1934, each of the undersigned agrees that a single joint Schedule 13D and any amendments thereto may be filed on behalf of each of the undersigned with respect to the securities held by each of them in Diamondback Energy, Inc.

Date: October 22, 2012

DB Energy Holdings LLC

By:   Wexford Capital LP, its Manager

By:   Wexford GP LLC, its General Partner

By:   /s/ Arthur H. Amron                            

Arthur H. Amron

Vice President and Assistant Secretary

Wexford Capital LP

By:   Wexford GP LLC, its General Partner

By:   /s/ Arthur H. Amron                            

Arthur H. Amron

Vice President and Assistant Secretary

Wexford GP LLC

By:   /s/ Arthur H. Amron                                    

Arthur H. Amron

Vice President and Assistant Secretary

By:   /s/ Joseph M. Jacobs                                             

Joseph M. Jacobs

By:   /s/ Charles E. Davidson                                        

Charles E. Davidson

Page 1 of 14