Chicago-based Bank One was the sixth-largest bank in the U.S. after a series of acquisitions when it was bought and subsumed by JPMorgan Chase & Co. in 2004. Bank One broke the sector's top-five ranks in 1998 when it bought hometown rival First Chicago NBD, increasing its assets to $260 billion.
Under CEO Jamie Dimon, appointed in 2000, Bank One lifted its assets to $320 billion and held its ground as the nation's sixth largest bank by 2004. Then JPMorgan Chase, then the country's second-largest bank with $801 billion in assets, snapped up Bank One for $58 billion in a deal that transformed the acquirer into a true global giant. The Bank One brand has since been swallowed up but Dimon has prospered at JPMorgan Chase, landing the CEO's spot in December 2005 following a year-and-a-half stint as president.