The Dow Jones industrial average closed more than 0 points lower Friday, only the ninth time in history of which has happened.
The index posted a loss of nearly 666 points, its sixth-worst decline ever on a points basis.
The last time the index posted a drop of more than 0 points was June 24, 2016, the day after the Brexit vote.
The eight different times the Dow closed more than 0 points lower all took place from the last 18 years. Half occurred during the financial crisis in 2008.