Apple shares jump on Carl Icahn's 'large' stake Mr Icahn's remarks reinforced positive shareholder sentiment. We currently have a large position in Apple. We believe the company to be extremely undervalued," he said. Had a nice conversation with Tim Cook today. Discussed my opinion that a larger buyback should be done now. We plan to speak again. Mr Cook said last year that Apple would return $100bn of cash to shareholders by 2015, including $60bn of share buybacks - up from a pledge of $10bn the year before. The exact size of Mr Icahn's investment in Apple is not yet known but Bloomberg reported that it is more than $1bn. Apple generally remains silent on this sort of issue, but issued a statement shortly after Mr Icahn's disclosures. We appreciate the interest and investment of all our shareholders. Tim [Cook] had a very positive conversation with Mr Icahn today," it said.