Stocks open lower; data, Greece eyed By: CNBC.com News May 29, 2015 at 09:30 AM EDT U.S. stocks opened lower on Friday, the last day of trade for the month, as investors eyed economic data and continued concerns about Greece. Read More >> Related Stocks: Altera Corp Big Lots Equinix Inc GameStop Corp Intel Corp Interxion Holding Ord Shs Manning & Napier Inc