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Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ( Mark One ) ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended : December 31 , 2020 or For the transition period from Commission File Number : 001-33480 CLEAN ENERGY FUELS CORP . ( Exact name of registrant as specified in its charter ) Delaware ( State or other jurisdiction of incorporation or organization ) Title of each class Common stock , $ 0.0001 par value per share 4675 MacArthur Court , Suite 800 , Newport Beach , CA 92660 ( Address of principal executive offices , including zip code ) Securities registered pursuant to Section 12 ( b ) of the Act : ( 949 ) 437-1000 ( Registrant's telephone number , including area code ) to Trading Symbol ( s ) Accelerated filer > CLNE 33-0968580 ( IRS Employer Identification No. ) Securities registered pursuant to section 12 ( g ) of the Act : None No No > 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 Name of each exchange on which registered The Nasdaq Stock Market LLC ( Nasdaq Global Select Market ) 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 Non - accelerated filer 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 . Large accelerated filer Smaller reporting company П Emerging growth company 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 . X Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Act ) . Yes No > The aggregate market value of the voting stock held by non - affiliates of the registrant as of June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter , was approximately $ 320,768,899 . The treatment of persons as affiliates of the registrant for purposes of this calculation is not , and shall not be considered , a determination as to whether any such person is an affiliate of the registrant for any other purpose . As of March 3 , 2021 , there were 199,221,936 shares of the registrant's common stock , par value $ 0.0001 per share , issued and outstanding . DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant's definitive proxy statement for its 2021 annual meeting of stockholders are incorporated by reference in Part III of this report .