FILE PHOTO: James "Jamie" Dimon, chief executive officer of JPMorgan Chase & Co., pauses during a break in sessions on the opening day of the World Economic Forum (WEF) in Davos, Switzerland, on Wednesday, Jan. 22, 2014. Dimon, whose eight years atop JPMorgan Chase & Co. have made him one of Wall Streets most powerful leaders, said hell start treatment for throat cancer, raising new questions about succession plans at the biggest U.S bank. Photographer: Jason Alden/Bloomberg via Getty Images