Jamie Dimon

The one-time protégé of former Citigroup chief Sandy Weill, Dimon is the chairman and CEO of JP Morgan Chase & Co.

Having worked with Weill for over two decades early in his career from American Express to Traveler's, Dimon forged his own destiny when he accepted the top job at Chicago's Bank One. Dimon rapidly ascended the corporate ladder after negotiating Chicago Bank One's sale to JP Morgan and then becoming CEO within four years.

Known for his trimming costs, and efficiency, Dimon has never been known for his subtlety. Likely to harangue employees for overspending and openly disparage senior execs in big meetings, he's a notoriously tough manager. However, his relative cautiousness in the run-up to the market downturn saved the JP Morgan and allowed Dimon to afford to sweep in and scoop up an imploding Bear Stearns in early 2008, which may very well go down as the greatest coup of Dimon's career. [Image via Getty]