The United Kingdom's 1992 currency and stock-market crisis was called Black Wednesday after Britain left the European Exchange Rate Mechanism.
The event occurred on September 16, 1992. The British government had joined the ERM, which linked currencies through agreed exchange-rate bands, but pressure mounted against the pound. The government raised interest rates and spent foreign-exchange reserves in an attempt to support sterling, yet it ultimately suspended the pound's ERM membership.
The episode caused major political damage to Prime Minister John Major's government and became a lasting symbol of failed exchange-rate policy. George Soros became widely associated with the crisis after his fund reportedly made a large profit betting against the pound, although many traders participated in the market pressure.
Black Wednesday is sometimes confused with a conventional share-price crash. Its central feature was a currency and monetary crisis, but it also produced major turmoil in financial markets and is commonly included in accounts of modern market crises.