On September 26, 2023, Mark Zinkula, a member of the Board of Directors (the ?Board?) of Diamond Hill Investment Group, Inc. (the ?Company?), notified the Company of his resignation from the Board, effective immediately, to fully devote himself to his new role as President and Chief Executive Officer of Thornburg Investment Management, Inc. In connection with the resignation of Mr. Zinkula, pursuant to the Company?s Amended and Restated Code of Regulations, the Board reduced the size of the Board from seven directors to six directors.