The 2009 TIME 100

Warren Buffett famously said that when the tide goes out, you find out who is swimming naked and who isn't. Well, JPMorgan Chase CEO Jamie Dimon still appears to be wearing his pants. As head of the second largest bank in America by assets, Dimon, 53, has found himself serving not only as captain of his own behemoth financial ship but also, as his Bear Stearns and Washington Mutual deals showed, as an occasional life raft for the U.S. government in its efforts to stave off financial calamity.

Known for his blunt mouth and detailed operational expertise, Dimon currently sits atop a massive financial institution that in the most recent quarter was lending $150 billion in more than 50 countries. While many of his peers assumed trillions in risk with pennies in reserve, Dimon's superior risk management, along with some taxpayer help, made it possible to dodge the early bullets that took down institutions like Merrill Lynch, Bear Stearns, Wachovia and Lehman Brothers. Still, his greatest challenges may lie ahead, especially if rising unemployment and lower home prices continue to blow hard against JPMorgan Chase's consumer-credit and commercial-real estate businesses. At a time when millions of Americans are underwater financially and scouring the beach for answers, he'll need all his management skills to navigate an even lower tide.

Ratigan is a co-creator and the former host of CNBC's Fast Money