Investors Are Dying to Bet Against Groupon

Want to short Groupon's stock? Get in line: the financially questionable online discounter is now ranked in the absolute most expensive category of stocks to bet against. Some 5.5 percent of the company's shares are out to short investors, versus 3.3 percent for an average S&P 500 issue.

"There is a perception out there that this business model is easily duplicated and thus, the valuation is not justified," a financier told Bloomberg. New York research firm Data Explorers rates Groupon a 10 out of 10 on cost of shorting. But then, when you calculate the cost of going long on an insolvent, unstable internet startup, that (apparently!) doesn't sound too bad.

[Photo of Groupon CEO Andrew Mason celebrating the company's Nov. 4 IPO via AP]