Duff & Phelps is a subsidiary of Virtus Investment Partners ( NASDAQ : VRTS ) , an asset management company with $ 24.4 billion under management ( as of November 30 , 2008 ) . Virtus provides investment management products and services to individuals and institutions through a multi-manager asset management business , comprising a number of individual affiliated managers , each with a distinct investment style , autonomous investment process and individual brand . Additional information can be found at www.virtus.com.