FBN's Charlie Gasparino on founder and CEO of Pershing Square Capital Management Bill Ackman dumping his entire stake in Valeant, and the possibility of changing his investment strategy. Shares of Herbalife (HLF) are surging this year, but company executives are taking no chances against their old nemesis, hedge fund manager Bill Ackman, as they press legislation in Congress to make life much more difficult for investors who try to make money betting on a stock’s collapse, FOX Business Network has learned.