It's not every day that a company with a market cap of more than US$ 70 billion , and one that is favoured by a lot of savvy investors, loses 80% in nine months . But that's what has happened with investors in the Canada-based Valeant Pharmaceuticals , where a spate of scams has been discovered over the past few months - from bad M&A accounting, to wrongful income reporting, and now the company is facing a potential default.