What Kind of Downside Versus Upside Could a Short Seller Expect?

"I won't even look at something unless I think I can make 60% to 90% return," he says. "An acid test would be if this company went out of business tomorrow, would anyone miss them? Well, they'd miss Disney." He's never shorted anything that he view as legit: "I like guys, I like shorting guys who try to create a stock"