Mallinckrodt stock tumbles after new Citron Research report targets $40,000-a-vial drug By: MarketWatch June 05, 2017 at 11:47 AM EDT The short-seller claimed a recent development could send Mallinckrodt shares to zero and make the company bankrupt. Read More >> Related Stocks: Express Scripts Holding Mallinckrodt plc Valeant Pharmaceuticals International, Inc.