A report by The Washington Post confirmed Northern California as the location of the first U.S. coronavirus case of unknown origin.
As President Donald Trump tried to ease concerns over the coronavirus, the U.S. stock futures traded lower with the Dow futures falling 53 points.
Continuing the trend, S&P 500 futures and Nasdaq 100 futures slid at least 0.2% each.
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Trump said in a news conference the risk of coronavirus to people in the U.S. is still “very low.”
He added the U.S. is going to “spend whatever’s appropriate” to deal with the virus.
Trump also put Vice President Mike Pence in charge of the U.S. response to the coronavirus.
The president said stocks should recover from their recent swoon.
But as Trump spoke, the Washington Post report added to concerns that the coronavirus is spreading at a rapid pace, hitting stock futures.
Worries over how the coronavirus will impact corporate profits and global economic growth have roiled the U.S. stock market this week as the number of confirmed cases increases.
South Korea has confirmed a total of more than 1,200 cases. About 400 people have contracted the virus in Italy.
After a record high earlier this month, the Dow has fallen more than 8%.