 COLUMBUS, Ohio, April 27, 2021 PRNewswire -- Diamond Hill Investment Group, Inc. NASDAQ:DHIL today reported unaudited financial results for the first quarter of 2021. The following are selected highlights for the quarter ended March 31, 2021: Assets under management AUM were 30.6 billion compared with 26.4 billion as of December 31, 2020, and 17.5 billion as of March 31, 2020. 