Apple said Thursday it is weighing ways to give shareholders more of its huge cash stockpile, after hedge fund Greenlight Capital filed suit in an effort to press it in that direction. Greenlight sued the maker of iPhones and iPads to block a shareholder vote that includes a management-backed proposal to make it impossible for the Apple board to issue preferred stock without shareholder approval. Greenlight said in a letter to shareholders that it wants Apple to issue "perpetual preferred stock" to distribute a bounty from the $137 billion in cash the company is holding.