Drugmaker Valeant faces debt default risk; shares plunge 50 percent

The news from the Canadian drugmaker, which also slashed its 2016 sales and earnings outlook, prompted Bill Ackman, whose Pershing Square Capital Management is one of Valeant's largest shareholders, to tell investors that he would take a much more active role there. For years, Valeant was an investor darling, buying up assets and delivering double-digit profit growth. During a more than two-hour conference call on Tuesday, Wall Street analysts pressed Chief Executive Officer Michael Pearson for