The U.S. Department of Labor says that applications for unemployment benefits surged by 70,000 last week, indicating that coronavirus-related quarantines are having an effect on the U.S. job market.

Following the announcement, the Dow Jones Industrial average opened slightly down, losing about 400 points.

The news comes the day after the Dow fell 1,333 points, or 6.3 percent on Wednesday. For the fourth time in about a week, losses triggered a "circuit-breaker" — a 15-minute halt in trading prompted by losses of at least 7 percent of the market share.

The market closed at under 20,000 for the first time in more than three years on Wednesday and the Dow fell below the point it was at in January 2017, when President Donald Trump took office.

Following Wednesday's close, the New York Stock Exchange said it would close its famous trading floor to help prevent the spread of COVID-19, but markets would remain open with electronic trading.