With that in mind, let's look at the four S&P 500 stocks that have the highest percentage of their available share-float sold short, according to the latest available figures from S&P Capital IQ. J.C. Penney, short position: 55.5% of float and 25.6% of outstanding shares This retailer's recent travails are well known, as J.C. Penney tried and failed to transform itself from a coupon-driven discount retailer to a more attractive destination for shoppers. With the Ron Johnson experiment having backfired, the company has recently started to move back toward its original focus, albeit trying to hang onto some of the progress it has made with store renovations and in-store specialty shops. Despite recent news that George Soros has taken a substantial position in the stock, short-sellers think that the retailer is doomed to eventual failure as its competitors have already taken advantage of its weakness.