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Table of Contents ( Mark One ) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 or TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from Commission File Number : 001-38090 Delaware ( State or other jurisdiction of incorporation or organization ) FORM 10 - K Large accelerated filer Non - accelerated filer □ SOLARIS OILFIELD INFRASTRUCTURE , INC . ( Exact name of registrant as specified in its charter ) 9811 Katy Freeway , Suite 700 Houston , Texas ( Address of principal executive offices ) Title of Each Class Class A Common Stock , $ 0.01 par value to 81-5223109 ( I.R.S. Employer Identification No. ) ( 281 ) 501-3070 ( Registrant's telephone number , including area code ) ( Former name , former address and former fiscal year , if changed since last report ) Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) " SOI " Securities registered pursuant to Section 12 ( g ) of the Act : None 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 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 Accelerated filer X Smaller reporting company Emerging growth company 77024 ( Zip code ) Name of each exchange on which registered New York Stock Exchange 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 . No No 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 Aggregate market value of the voting and non - voting common equity held by non - affiliates of Registrant as of June 30 , 2020 : $ 214,610,750 As of February 18 , 2021 , the registrant had 30,148,968 shares of Class A common stock , $ 0.01 par value per share , and 15,178,649 shares of Class B common stock , $ 0.00 par value per share , outstanding . DOCUMENTS INCORPORATED BY REFERENCE Portions of the definitive proxy statement relating to the Registrant's 2020 Annual Meeting of Shareholders are incorporated by reference into Part III of this Annual Report on Form 10 - K .