 Shares of Comcast Corp. CMCSA, -6.25 bounced 0.9 in premarket trading Wednesday, off the previous sessions 2 12-year closing low, after the cable TV and internet provider boosted its share repurchase program to 20 billion. So far this year, the company said it has repurchased 9 billion of its common stock, which represents 6.1 of its market capitalization of 147.67 billion as of Tuesdays stock closing price. 