A trader works at the New York Stock Exchange in New York, the United States, on May 21, 2018. U.S. stocks closed higher on Monday. The Dow rose 1.21 percent to 25,013.29, and the S&P 500 rose 0.74 percent to 2,733.01, while the Nasdaq increased 0.54 percent to 7,394.04. (Xinhua/Wang Ying)