Although short selling -- the practice of selling borrowed shares with the hope of repaying the loan by buying back the shares at a lower price -- goes against the American belief that stocks always go up, I have long been fascinated with it. Short Stories discusses what works, what doesn't, and what some of the leading lights in shorting stocks think about its opportunities and threats. I describe possible short trades and I seek your comments and questions for story ideas. I don't offer any investment advice and I don't trade on any of the posts I write.

I first suggested selling short Bally Total Fitness, Inc. (Pink Sheets: BFTH) last November at $2.59. Why? Bally owed $512 million this year, was spending $7 million more cash than it was taking in, and I doubted that banks would lend it enough money to stay afloat. Back then my biggest concern for the short position was that hedge fund billionaire Stevie Cohen had placed a big bullish bet on Bally -- his SAC Capital Advisors owned 6.9% of the company. I figured he must know something that I didn't.

But on Thursday, Cohen's bet went bust as Bally filed for bankruptcy. According to its filing, "Under the prepackaged restructuring plan, there will be a reduction in the principal outstanding on Bally's existing senior subordinated notes by $150 million by exchanging all existing senior subordinated notes for a new class of notes, common equity and the right to participate in a $77.5 million rights offering."

SAC's wipe out provides a useful insight for investors -- even the most talented players make mistakes. It's just that they make more good calls than bad ones. Meanwhile, those who followed my suggestion to short Bally could cover their position on Monday at $0.31 a share, pocketing a 736% return -- not bad for eight month's work.

Peter Cohan is President of Peter S. Cohan & Associates, a management consulting and venture capital firm. He also teaches management at Babson College and edits The Cohan Letter. He has no financial interest in Bally.