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

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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

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A trader at the New York Stock Exchange watches a monitor moments before the Federal Reserve announced it would keep interest rates low through at least 2013. The news reassured investors and helped sustain a rally. Mario Tama/Getty Images hide caption

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