Pershing Square buys up 16.5% of J.C. Penney

A Friday regulatory filing revealed that Pershing Square Capital Management, an activist hedge fund firm run by Bill Ackman, has taken a 16.5% stake of J.C. Penney Co. According to the New York Times, the move signals an intent by Ackman to shake up the retailer, as the filing came in a 13D form, which is used by activist investors to indicate an interest in effecting some sort of change. The hedge fund manager had previously invested in Borders Group and Target.