As an investor, it's always important to understand both sides of the investing story. Great investors seek out what they may be missing in their thesis. But which well-known hedge fund manager would you not want to be betting against?

In this segment of The Motley Fool's financials-focused show, Where the Money Is, banking analysts Matt Koppenheffer and David Hanson give their dreaded adversaries. David highlights why he wouldn't want to bet against Bruce Berkowitz because of the detailed research his team has historically prepared, such as their work on Fannie Mae (FNMA 1.57%), Freddie Mac (FMCC 2.80%), and AIG (AIG 0.88%). Matt gives his reason for being wary of disagreeing with George Soros.