Early movers: TRV, GM, LUV, UA, DHI, AXP & more By: CNBC.com News April 21, 2016 at 08:02 AM EDT These are the stocks posting the largest moves before the bell. Read More >> Related Stocks: American Express Apple Citrix Systems D.R.Horton GNC Holdings Inc General Motors Las Vegas Sands Mattel PulteGroup Qualcomm, Inc. Sanofi-Aventis S.A. ADR Southwest Airlines Stanley Black & Decker TravelersCompanies Under Armour Vitamin Shoppe Inc Wal-Mart Stores, Inc. Yahoo Yum Brands