The largest investment outsourcing managers

With 453 clients -- the most in the group -- SEI has $67.1 billion under management. (Pictured is SEI's offices courtesy of the firm)

With 400 clients, Mercer has $73.9 billion under management. (Pictured is Mercer's headquarters)

With 231 clients, Cambridge Associates has $87.5 billion under management. (Pictured is Camrbidge's headquarters courtesy of the firm)

Russell's headquarters