What nickname identifies the sharp fall in UK markets on September 16, 1992?

The sharp fall in UK markets on September 16, 1992, is known as Black Wednesday.

The crisis occurred when Britain was part of the European Exchange Rate Mechanism, which required the pound to remain within an agreed range against other European currencies. Persistent pressure forced the British government to raise interest rates and spend foreign reserves defending the pound’s value.

Those measures failed. On September 16, Chancellor Norman Lamont announced further interest-rate increases, followed later by Britain’s withdrawal from the exchange-rate mechanism. The pound then depreciated sharply, and the day became known as Black Wednesday.

The event is often confused with a conventional stock-market crash because it centered on foreign-exchange markets and monetary policy rather than a single exchange’s share-price collapse. It nevertheless produced major financial-market losses and a serious political setback for the Conservative government. Britain eventually benefited from greater freedom to set interest rates, but the episode permanently changed debate over European monetary integration.