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Billionaire investor Carl Icahn said Apple Inc's stock was "still dramatically undervalued" and that it should be trading at $240, up from his earlier estimate of $216.
Apple shares rose as much as 1.4 per cent to $130.32 by midday on Monday. The stock has gained more than a quarter since October, when Icahn first said it was undervalued.
Icahn said on Monday it was time for the iPhone maker to execute a much larger share buyback. Apple boosted its share repurchase programme in April to $140 billion from $90 billion announced last year and raised quarterly dividend by 11 per cent to 52 cents per share.
"It is our belief that large institutional investors, Wall Street analysts and the news media alike continue to misunderstand Apple," Icahn wrote in an open letter to Chief Executive Tim Cook.
