It has been an ugly stretch for US stocks, which was capped by Wednesday’s more-than-830-point tumble for the Dow Jones Industrial Average.

To recap: The Dow and the S&P 500 index booked their worst one-day slumps since February 8, while the Nasdaq Composite Index put in its worst single-session skid since Brexit, when the UK voted to exit from the European Union, roiling global markets in 2016.