Dow tumbles nearly 1,000 points again, because Wall Street can't figure out coronavirus

``This roller coaster of a week has given investors whiplash. The Dow posted two of its best days in history in terms of points gained on Monday and Wednesday, and one of its worst point losses Tuesday. That has unnerved many people with stock-heavy 401(k)s, which have been whipsawed. The wild swings stem from mixed signals about the economy: The coronavirus outbreak threatens to seriously dent global growth. But how long will the downturn last, and how will it affect the United States?''