I was teaching managed exchange rates with my AS Level class and couldn’t get away from the events in Britain on the 16th September 1992 – known as Black Wednesday. On this day the British government were forced to pull the pound from the European Exchange Rate Mechanism (ERM).
The Exchange Rate Mechanism (ERM) was the central part of the European Monetary System (EMS) and its purpose was to provide a zone of monetary stability – the ERM was like an imaginary rope (see below), preventing the value of currencies from soaring too high or falling too low in realtion to one another.
It consisted of a currency band with a ‘Ceiling’ and a ‘Floor’ through which currencies cannot (or should not) pass and a central line to which they should aspire. The idea is to achieve the mutual benefits of stabel currencies by mutual assistance in difficult times. Participating countries were permitted a variation of +/- 2.25% although the Italian Lira and the Spanish Peseta had a 6% band because of their volatility. When this margin is reached the two central banks concerned must intervene to keep within the permitted variation. The UK persistently refused to join the ERM, but under political pressure from other members agreed to join “when the time is right”. The Chancellor decided that this time had come in the middle of October 1990. The UK pound was given a 6% variation
Although it stood apart from European currencies, the British pound had shadowed the German mark (DM) in the period leading up to the 1990s. Unfortunately, Britain at the time had low interest rates and high inflation and they entered the ERM with the express desire to keep its currency above 2.7 DM to the pound. This was fundamentally unsound because Britain’s inflation rate was many times that of Germany’s.
Compounding the underlying problems inherent in the pound’s inclusion into the ERM was the economic strain of reunification that Germany found itself under, which put pressure on the mark as the core currency for the ERM. Speculators began to eye the ERM and wondered how long fixed exchange rates could fight natural market forces. Britain upped its interest rates to 15% (5% in one day) to attract people to the pound, but speculators, George Soros among them, began heavy shorting* of the currency. Spotting the writing on the wall, by leveraging the value of his fund, George Soros was able to take a $10 billion short position on the pound, which earned him US$1 billion. This trade is considered one of the greatest trades of all time.
* In finance, short selling is the practice of selling assets, usually securities, that have been borrowed from a third party (usually a broker) with the intention of buying identical assets back at a later date to return to that third party. The short seller hopes to profit from a decline in the price of the assets between the sale and the repurchase, as the seller will pay less to buy the assets than it received on selling them. Wikipedia.