Traders work on the floor at the opening bell of the Dow Industrial Average at the New York Stock Exchange on December 6, 2018 in New York. - Wall Street opened sharply lower Thursday, joining a global stocks sell-off after the arrest of a key Chinese executive at Washington's request revived worries over trade tensions. About three minutes into trading, the Dow Jones Industrial Average had fallen 2.0 percent, nearly 500 points, to 24,532.25. The broad-based S&P 500 sank 1.9 percent to 2,648.04, while the tech-rich Nasdaq Composite Index shed 2.2 percent to 7,002.02. (Photo by Bryan R. Smith / AFP)