 Shares of Crown Holdings Inc. CCK, 9.09 charged up 9.5 in midday trading Thursday, after Carl Icahn disclosed an 8.5 activist stake in the maker of packaging products and equipment for consumer goods, enough to make him the second-largest shareholder according to FactSet data. In a 13D filing with the Securities and Exchange Commission, Icahn said he believed the stock was undervalued and represented an attractive investment opportunity. 