Early movers: GM, CAT, CMCSA, MMM, LUV, T & more By: CNBC.com News October 23, 2014 at 08:27 AM EDT These are the stocks posting the largest moves before the bell. Read More >> Related Stocks: 3M Co AT&T Inc Atlantic Power Corp CarMax Caterpillar Cheesecake Fact Citrix Systems Comcast Corp Comcast Corp Dunkin' Brands Group Eli Lilly General Motors Nokia Corp ADR Procter & Gamble PulteGroup Quest Diagnostics Seagate Technology Plc Southwest Airlines Tractor Supply Under Armour Visa Yelp Inc