Carl Icahn: Apple should launch $150B stock buyback NEW YORK Activist investor Carl Icahn has told Apple CEO Tim Cook that the iPhone and iPad maker should launch a $150 billion stock buyback immediately and disclosed that he now owns 4.7 million shares in the company. In a letter to Cook posted online on Thursday, Icahn said he has increased his stake in Apple (AAPL) by 22 percent from 3.9 million at the end of September. At Apple's current stock price, that's worth about $2.5 billion and amounts to less than a 1 percent stake in the company. Icahn wants Apple to launch the buyback at its current stock price, which closed at close to $525 on Wednesday when the letter was sent. The billionaire investor posted the letter on a new website he launched Thursday, called "Shareholders Square Table."