Stocks Fall at Open Amid Worries Over Greece By: CNBC.com News January 30, 2012 at 09:31 AM EST Stocks tumbled at the open Monday as investors were cautious amid the EU summit in addition to growing worries over Greece's debt-restructuring deal. Read More >> Related Stocks: Alkermes Plc Bank of America Citigroup Delta Air Lines JPMorgan Chase & Co Morgan Stanley