Wall Street suffered its worst day in four months, as the latest blow in the U.S.-China trade war roiled Monday’s stock market, The New York Times reports. The benchmark S&P 500 fell 2.4 percent in just one day, and CNN reports that the Dow also fell 2.4 percent, while NASDAQ dropped by 3.4 percent. The plunge came just hours after China announced tariffs on nearly $6o billion worth of U.S. goods, the latest escalation in a burgeoning trade war between the global powers. Last week, as the two sides appeared to come close to a deal, Trump announced higher tariffs on $200 billion worth of Chinese exports, and negotiations stumbled. Gregory Daco, chief U.S. economist at consulting firm Oxford Economics, told the Times that if the trade war continues, “This would essentially be another thorn in the global economy’s side.”