The New York Stock Exchange said Wednesday it will temporarily close its historic trading floor and move fully to electronic trading after two people tested positive for coronavirus infection at screenings it had set up this week.

All-electronic trading will begin on March 23 at the open, the exchange said. The facilities to be closed are the NYSE equities trading floor and NYSE American Options trading floor in New York, and NYSE Arca Options trading floor in San Francisco.

The closure was in part as a result of positive coronavirus tests of two people, Stacey Cunningham, President of the NYSE, told CNBC. The entrants were stopped at the medical screenings at the Big Board.