In a Stock Sharks interview posted last month, Kevin O'Leary didn't hesitate to name a stock that had slaughtered him. "I shorted Yahoo. I got slaughtered. It got added to the S&P 500," he said. The inclusion sent the stock up, and his broker started calling. "They kept calling me on margin calls ... every four hours cuz I was losing three, 4 million an hour," he said. "It went from like eight bucks to $280."
The damage, by his telling, was close to half of everything he had. The trade "basically took my net worth down almost by, I can't remember, it was a huge percentage, 40, 50%," he said. He didn't put a dollar figure on it.
