The foreign exchange market

Exchanging currency means trading one currency for another. The value at which an exchange takes place is called the exchange rate, which can be regarded as the price of one currency expressed in terms of another one, such as £1 (GBP) exchanging for US$1.50 cents.

When nations are formed, they commonly introduce their own currency as a mark of independence, rather than share the currency of another country. For example in 1792, shortly after independence from Britain, the USA introduced the dollar as its official currency in preference to the British pound. The word dollar is derived from thaler, a European word for the silver coinage which was commonly used across Europe between the 15th and 18th century. The British pound itself is at least 1300 years old and is the world’s longest surviving currency.  However, it is the Chinese who can claim the world’s first coins, some 3000 years ago, and its first paper money, used about 1200 years ago, although paper money disappeared in China in the 15th Century. The most recent currency to be added to the stock of world currencies is the European euro, which came into existence in 1999

(Source: Davies, Glyn. A history of money from ancient times to the present day, University of Wales Press, 2002.)

Today, currencies are issued and controlled by central banks, such as the European Central Bank (ECB), the US Federal Reserve, and the Bank of England. The two main global currencies are the US Dollar ($) and the European Euro (€). The Euro is shared by sixteen European countries as part of European integration that dates back to the 1950s.

The market for foreign exchange

Currencies are bought and sold, just like other commodities, in markets called foreign exchange markets.  The world’s three most common transactions are exchanges between the dollar and the euro (30%) the dollar and the yen (20%) and the dollar and the pound Sterling (12%).

How currency values are established depends upon whether they are determined solely in free markets, called freely floating, or determined by agreements between governments, called fixed or pegged. Like most currencies, the pound has at times been both fixed, and floating. Between 1944 and 1971, most of the world’s currencies were fixed to the US Dollar, which in turn was fixed to gold.  After a period of floating, the pound joined the European Exchange Rate Mechanism (ERM) in 1990, but quickly left in 1992, and has floated freely ever since. This has meant that its value is largely determined by the interaction of demand and supply.

The demand for currency

The demand for currencies is derived from the demand for a country’s exports, and from speculators looking to make a profit on changes in currency values.

The supply of currency

The supply of a currency is determined by the domestic demand for imports from abroad. For example, when the UK imports cars from Japan it must pay in yen (¥), and to buy yen it must sell (supply) pounds. The more it imports the greater the supply of pounds onto the foreign exchange market. A large proportion of short-term trade in currencies is by dealers who work for financial institutions. The London foreign exchange market is the World’s single largest international exchange market.

Exchange rates

The equilibrium exchange rate is the rate which equates demand and supply for a particular currency against another currency.


If we assume the UK and France both produce goods that the other wants, they will wish to trade with each other. However, French producers require payment in Euros and the British producers require payments in pounds Sterling. Both need payment in their own local currency so that they can pay their own production costs in their local currency. The foreign exchange market enables both French and British producers to exchange currencies so that trades can take place.

The market will create an equilibrium exchange rate for each currency, which will exist where demand and supply of currencies equates.

Changes in exchange rates

Changes in the value of a currency like Sterling reflect changes in demand and supply. On a demand and supply graph, the price of Sterling is expressed in terms of the other currency, such as the $US.

An increase in the exchange rate

For example, an increase in exports would shift the demand curve for Sterling to the right and push up the exchange rate. Originally, one pound bought $1.50, but now buys $1.60, hence its value has risen.

Exchange rates and interest rates

Changes in a country’s interest rates also affect its currency, through its impact on the demand and supply of financial assets in the UK and abroad. For example, higher interest rates relative to other countries, makes the UK attractive the investors, and leads to an increase in the demand for the UK’s financial assets, and an increase in the demand for Sterling.

Conversely, lower interest rates in one country relative to other countries leads to an increase in supply, as speculators sell a currency in order to buy currencies associated with rising interest rates. These speculative flows are called hot money, and have an important short-term effect on exchange rates.