Considered by her boss, Jamie Dimon, to be one of the quickest minds he’s encountered, Lake plays more of a copilot’s role in running America’s largest bank. The CEO’s mention of Lake in a succession-planning missive early this year solidified her status on a short list of candidates for the top job when Dimon eventually retires. Lake’s shepherding of the bank’s stress-testing submissions has helped JPMorgan Chase mostly sail through the process while allowing it to up its dividends and other shareholder payouts.