Traders on the floor of the New York Stock Exchange on Monday. Spencer Platt/Getty Images hide caption

itoggle caption Spencer Platt/Getty Images

In this Oct. 20, 2012 photo, people line up to enter a newly opened Apple Store in Beijing. Exxon has once again surpassed Apple as the world's most valuable company after the iPhone and iPad maker saw its stock price falter. Andy Wong/AP hide caption

itoggle caption Andy Wong/AP