The historic New York Stock Exchange trading floor will temporarily shut down after two people tested positive this week.

Instead, the exchange will begin fully electronic trading, which will begin on Monday, according to CNBC. Among the facilities set to close because of the pandemic are the NYSE equities trading floor and NYSE American Options trading floor in New York, plus the NYSE Arca Options trading floor in San Francisco.

Stacey Cunningham, president of the NYSE, said the changes are being implemented because two people tested positive during screenings that had been set up on the trading floor.

“We implemented a number of safety precautions over the past couple of weeks and, starting on Monday this week, we started preemptive testing of employees and screening of anyone who came into the building,” Cunningham said.

“If that screening warranted additional testing, we tested people, and they were sent home and not given access to the building. A couple of those test cases have come back positive,” Cunningham added.

The move comes the same day that the Dow Jones Industrial index fell 6.25% from Tuesday’s close and finished at 19,909.98 points, wiping out nearly all gains since President Trump was inaugurated.

New York City has seen a huge surge in COVID-19 cases, with numbers in the city growing to almost 1,900 as of Wednesday afternoon. New York City Mayor Bill de Blasio is pushing to implement a shelter-in-place order for the nation’s largest city.

In the United States, there have been at least 7,769 cases of the coronavirus, 106 recoveries, and 118 deaths, according to the latest reading by the Johns Hopkins University tracker.