Early movers: S, TWTR, AXP, GM, MAR, NFLX & more By: CNBC.com News July 30, 2014 at 07:45 AM EDT These are the stocks posting the largest moves before the bell. Read More >> Related Stocks: ADT Corp AT&T Inc Almirall Sa American Express Amgen Astrazeneca Plc ADR Atlantic Power Corp Express Scripts Holding Garmin Ltd General Motors Humana Marriott International Netflix Pitney Bowes Rockwell Automation Sealed Air Sentinelone Inc Cl A Twitter, Inc. United States Steel Corp