Apollo agreed to invest in Siebert Williams Shank, a full-service investment banking and financial services firm. Financial terms were not disclosed. “Since inception, SWS has sought to continue to grow in scope and capabilities to better serve our clients. This strategic partnership will certainly enhance our capacity and competitive position in the capital markets and maintain our strong performance-based culture as we serve clients globally,” Suzanne Shank, Siebert Williams Shank President & CEO.