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Table of Contents ( Mark One ) ☑ United States Securities and Exchange Commission Washington , D.C. 20549 Form 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 or TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 000-24498 DIAMOND HILL INVESTMENT GROUP DIAMOND HILL INVESTMENT GROUP , INC . ( Exact name of registrant as specified in its charter ) Ohio ( State of incorporation ) Title of each class 65-0190407 ( I.R.S. Employer Identification No. ) 325 John H. McConnell Blvd , Suite 200 , Columbus , Ohio 43215 ( Address of principal executive offices ) ( Zip Code ) Registrant's telephone number , including area code : ( 614 ) 255-3333 Securities registered pursuant to Section 12 ( b ) of the Act : Common shares , no par value Trading Symbol DHIL Name of each exchange on which registered The NASDAQ Stock Market 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 . 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 No ☑ Yes □ No ☑