Steve Mandel , founder and manager of Lone Pine Capital, recently added enough shares to his stake in Charter Communications Inc , currently the third-largest cable operator in the United States, to make it one of his top 20 stakes by volume. On July 6, Mandel acquired 3,010,321 shares of the Connecticut-based cable telecommunications company, previously the 30th-largest stake in his portfolio, paying an average price of $174.07 per share.