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( 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 FORM 10 - K TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Delaware ( State or other jurisdiction of incorporation ) OR Advent Technologies Holdings , Inc. ( Exact name of Registrant as specified in its Charter ) Securities registered pursuant to Section 12 ( b ) of the Act : Large accelerated filer Non - accelerated filer 001-38742 ( Commission File Number ) 200 Clarendon Street Boston , MA 02116 ( Address of principal executive offices ) ( Zip Code ) Registrant's telephone number , including area code : ( 857 ) 264-7035 Trading Symbol ( s ) ADN ADNWW 83-0982969 ( IRS Employer Identification No. ) Title of each class Common Stock , par value $ 0.0001 per share Warrants to purchase one share of common stock , each at an exercise price of $ 11.50 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 . YESNO > Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15 ( d ) of the Act . YES NO 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 Name of each exchange on which registered The Nasdaq Stock Market LLC The Nasdaq Stock Market LLC Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , 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 X