News Stock market plunge deepens, S&P 500 enters bear market, as coronavirus’ threat to the economy escalates March 12, 2020March 12, 2020Jessica Menton, USA TODAYComments Off on Stock market plunge deepens, S&P 500 enters bear market, as coronavirus’ threat to the economy escalates U.S. stocks tumbled into a bear market Thursday after President Trump banned travel from Europe to stem the economic fallout from the coronavirus.