Traders work on the floor of New York Stock Exchange in New York, the United States, April 9, 2018. U.S. stocks closed higher on Monday. The Dow increased 0.19 percent to 23,979.10, and the S&P 500 rose 0.33 percent to 2,613.16, while the Nasdaq increased 0.51 percent to 6,950.34. (Xinhua/Wang Ying)