Markets turned cautious again, erasing and early gain and ending lower as investors try to handicap how much the new coronavirus variant will impact the economy.

The latest roller-coaster ride brought the S&P 500 index up 1.9% in the morning and down 1.2% by the closing bell.

The afternoon reversal is the latest dizzying move in recent days as the omicron variant spreads.

Wall Street was already headed lower in the afternoon when the White House announced that the first confirmed case with the omicron variant had been found in the U.S., in a person who recently returned from South Africa.