Soon after quitting Merrill Lynch to run wealth management at Morgan Stanley in 2006, James Gorman remarked: "You've got to be brutal by defining the bottom half of your organisation."

His stance was unusual in a sector renowned for its louche behaviour. It gave Gorman, a former McKinsey & Co senior partner, a chance to stand out as something special as he succeeded in doubling Morgan Stanley's margins by the end of last year.