Even after central banks launched a co-ordinated economic support package on Sunday, markets plunged again hours later. One way to prevent a further slide, now being discussed, would be to close financial markets temporarily, as Franklin Delano Roosevelt did with US banks in 1933. Despite the magnitude of the falls, however, it is better that they remain open.

Advocates of closure say price discovery — markets’ primary function — has become almost impossible given the unpredictability of the economic damage. Markets can no longer act as vehicles for efficient allocation of capital, but are layering a financial crisis on top of an economic and health crisis.

But markets are not acting dysfunctionally. Violent securities price movements can sap economic confidence but are not in themselves signs that markets are not working. While price discovery is difficult, it should be allowed to continue. It is not better for the economy to have no public prices at all. Closing exchanges could create the very problems it is intended to prevent, as investors are shut out but struggle to value assets and meet redemptions. It is particularly important that small investors should not be excluded from trading, given that large investors will continue to trade privately.