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Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 ( 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 1934 TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF Form 10 - K For the transition period from Maryland ( State or Other Jurisdiction of Incorporation or Organization ) OR 1603 Orrington Avenue , Suite 1005 Evanston , Illinois ( Address of Principal Executive Offices ) FIDUS INVESTMENT CORPORATION ( Exact Name of Registrant as Specified in Its Charter ) Title of each class Common Stock , par value $ 0.001 per share 6.000 % Notes due 2024 5.375 % Notes due 2024 Commission file number : 814-00861 to ( 847 ) 859-3940 ( Registrant's Telephone Number , including Area Code ) Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) FDUS FDUSZ FDUSG 27-5017321 ( I.R.S. Employer Identification No. ) 60201 ( Zip Code ) Name of each exchange on which registered The NASDAQ Global Select Market The NASDAQ Global Select Market The NASDAQ Global Select Market Securities registered pursuant to Section 12 ( g ) of the Act : None No 区 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 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 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