Despite Mr. Ackman's bearish bet against Herbalife, the company has not been found to be a fraud. He's held on and has now made a tidy profit on his trade after months of being in the red. He had far less success with J. C. Penney, despite gaining a board seat and persuading the struggling retailer to hire Apple's then-vaunted head of retail, Ron Johnson. Later, Mr. Ackman's firm amassed a nearly 10 percent stake in Allergan and relentlessly tried to browbeat the drug manufacturer into deal talks. Yet Allergan ultimately chose to sell itself to Actavis, leaving Mr. Ackman without his initial preferred deal — but with a gigantic trading profit.