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Table of Contents U UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ANNUAL REPORT UNDER SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 OR TRANSITION REPORT UNDER SECTION 13 OR 15 ( d ) OF SECURITIES EXCHANGE ACT OF 1934 Commission File Number 001-35700 DE ( State or Other Jurisdiction of Incorporation or Organization ) 500 West Texas Suite 1200 Midland , TX ( Address of principal executive offices ) Title of Each Class Common Stock , par value $ 0.01 per share Diamondback Energy , Inc. ( Exact Name of Registrant As Specified in Its Charter ) Large Accelerated Filer Non - Accelerated Filer FANG X 45-4502447 ( I.R.S. Employer Identification Number ) ( Registrant Telephone Number , Including Area Code ) : ( 432 ) 221-7400 Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) Securities registered pursuant to Section 12 ( g ) of the Act : None 79701 ( Zip code ) Name of Each Exchange on Which Registered Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes > No The Nasdaq Stock Market LLC ( NASDAQ Global Select Market ) No No □ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T ( § 232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes No | Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company , or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company " and " emerging growth company " in Rule 12b - 2 of the Exchange Act : Accelerated Filer Smaller Reporting Company Emerging Growth Company 0 0 If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Exchange Act ) . Yes □ No 区 Aggregate market value of the voting and non - voting common equity held by non - affiliates of registrant as of June 30 , 2020 was approximately $ 6.6 billion . As of February 19 , 2021 , 158,015,647 shares of the registrant's common stock were outstanding . DOCUMENTS INCORPORATED BY REFERENCE Portions of Diamondback Energy , Inc.'s Proxy Statement for the 2021 Annual Meeting of Stockholders are incorporated by reference in Items 10 , 11 , 12 , 13 and 14 of Part III of this Form 10 - K .