Pershing Square’s Bill Ackman and Valeant Pharmaceuticals International’s Michael Pearson Interview

William “Bill” Ackman, founder and chief executive officer of Pershing Square Capital Management LP, pauses during a Bloomberg Television interview in New York, U.S., on Wednesday, April 23, 2014. Ackman already has a $1 billion paper gain on a newly disclosed 9.7 percent stake in Allergan Inc., helping to offset losses that his funds incurred through an earlier bet against Herbalife Ltd. Photographer: Scott Eells/Bloomberg via Getty Images