Carl Icahan served as special economic adviser to the President. : ​A billionaire investor and long-time ally of Donald Trump, sold more than $30m of shares in a company that depends heavily on steel, only days before the President announced plans to introduce tariffs on imports of the metal. Carl Icahan, who served as special economic adviser to the President before he resigned when a magazine article highlighted potential conflicts of interest, got rid of a total of $31.3m of stock in Manitowoc Company Inc.