Founder and president, Greenlight Capital
Overheard on Wall Street this year: "You've been Einhorned." No one moves markets quite like hedge fund manager David Einhorn, best known for publicly shorting (and quickly sinking) stocks he deems unworthy. Take Herbalife (, the nutritional supplement company that saw its stock plunge 20% one day last May when Einhorn raised questions about the company on a conference call with analysts and investors. Since then, his words have sent )Chipotle ( tanking, given )GM (Fortune 500) and , Cigna (Fortune 500) a nice boost, and have become so potent that the Wall Street Journal studied, in earnest, the "Einhorn Effect." (He's also won $4 million playing poker.) That's enough cultural currency to make up for his own fund's middle-of-the-pack performance -- it's up 13.2% this year through September -- and being slapped with an $11 million fine for insider trading in January. --EF ,
He's a pro-customer, tightfisted risk-taker who is conditioning Wall Street to embrace his erratic earnings. If you're running a business with high margins - watch out.