Private equity firm Stephens Capital Partners on Tuesday acquired a minority stake in QubicaAMF Worldwide, the companies announced in a news release Friday. Stephens Capital Partners is the principle investment arm of the Warren A. Stephens family and Stephens Inc., a full-service, privately-owned investment banking firm based in Little Rock, Arkansas, with offices across the U.S. and in Europe. Stephens, which has been in business since the 1930s and has been making private equity investments...