News Dow endures worst day since ‘Black Monday’; S&P 500 enters bear market as coronavirus spreads economic gloom March 12, 2020March 12, 2020Jessica Menton, USA TODAYComments Off on Dow endures worst day since ‘Black Monday’; S&P 500 enters bear market as coronavirus spreads economic gloom U.S. stocks tumbled into a bear market Thursday after President Trump banned travel from Europe to stem the economic fallout from the coronavirus.