After throwing in the towel on his fight to stop Michael Dell from taking his company private, activist investor Carl Icahn turned his attention to Apple. In October, Icahn shared an open letter that he wrote to Apple CEO Tim Cook. In the letter, titled "Sale: Apple Shares at Half Price," Icahn said that he believed Apple's stock price should be doubled. At the time of the letter, Apple's stock price sat at $100.80 per share, but Icahn believed that it should have been trading at $203 per share.