Early Movers: GMCR, GRPN & More By: CNBC.com News May 09, 2013 at 07:47 AM EDT These are the stocks posting the largest moves before the bell. Read More >> Related Stocks: Activision Blizzard Barnes & Noble BlackRock Citigroup Costco Wholesale Goldman Sachs Group Groupon Cl A Microsoft Monster Beverage Nintendo Ltd ADR Sony Corp Starbucks Corp Tesla, Inc. Transocean Ltd