The British Chancellor of the Exchequer, Norman Lamont, announced the decision at 7:30 PM. He raised interest rates twice that day, first to 12%, then to 15%, in a futile attempt to defend the pound’s mandated value against the German mark. The markets did not blink. By evening, the UK Treasury had spent an estimated £3.3 billion of its reserves. The government suspended sterling’s membership in the European Exchange Rate Mechanism (ERM), a system designed to limit currency fluctuations before a planned single currency. The pound fell 15% against the mark in the following weeks.
Black Wednesday exposed a fatal flaw in fixed-exchange-rate systems when confronted with concentrated speculative force. The UK was obligated to keep the pound above a floor of 2.7780 German marks. Hedge funds, most notably Soros Fund Management, borrowed pounds massively and sold them for marks, betting the British government could not sustain the defense. High German interest rates, set to control inflation after reunification, made the strong mark a safe haven. The UK’s weak economy could not tolerate the high interest rates needed to make the pound attractive.
The event is often framed as a genius bet by a single man. While Soros’s fund netted over $1 billion, the pressure was a market-wide phenomenon. Hundreds of banks and funds executed the same trade, smelling blood after the UK failed to secure a German rate cut. The Bank of England’s desperate, public interventions only signaled greater vulnerability.
The political and economic consequences were immediate and long-lasting. The Conservative government’s reputation for economic competence was shattered, contributing to its defeat in 1997. Paradoxically, the devaluation lowered borrowing costs and sparked an export-led recovery, laying groundwork for future growth. The trauma made the UK permanently skeptical of ceding monetary sovereignty, directly influencing its later refusal to adopt the euro.