Photo taken on March 24, 2020 shows the New York Stock Exchange and George Washington statue on Wall Street in New York, the United States. (Xinhua/Wang Ying)

NEW YORK, July 19 (Xinhua) -- U.S. stocks fell sharply on Monday morning with the Dow dropping more than 500 points shortly after the opening, as worries over a rebound in COVID-19 cases triggered market sell-off.