Early Movers: ARB, UPS, GBX & More By: CNBC.com News December 18, 2012 at 07:46 AM EST These are the stocks posting the largest moves before the bell. Read More >> Related Stocks: Allstate Corp American Railcar Ind Apple Boeing Co ConocoPhillips Greenbrier Companies McDonald's Corp Nielsen NV Toyota Motor Corp Ltd Ord ADR United Parcel Service Wal-Mart Stores, Inc.