In finance, an exchange rate is the rate at which one currency will be exchanged for another currency. Currencies are most commonly national currencies, but may be sub-national as in the case of Hong Kong or supra-national as in the case of the euro.
The exchange rate is also regarded as the value of one country's currency in relation to another currency. For example, an interbank exchange rate of 131 Japanese yen to the United States dollar means that ¥131 will be exchanged for or that will be exchanged for ¥131. In this case it is said that the price of a dollar in relation to yen is ¥131, or equivalently that the price of a yen in relation to dollars is $1/131.
Each country determines the exchange rate regime that will apply to its currency. For example, a currency may be floating, pegged (fixed), or a hybrid. Governments can impose certain limits and controls on exchange rates. Countries can also have a strong or weak currency. There is no agreement in the economic literature on the optimal national exchange rate policy (unlike on the subject of trade where free trade is considered optimal). Rather, national exchange rate regimes reflect political considerations.
In floating exchange rate regimes, exchange rates are determined in the foreign exchange market, which is open to a wide range of different types of buyers and sellers, and where currency trading is continuous: 24 hours a day except weekends (i.e. trading from 20:15 GMT on Sunday until 22:00 GMT Friday). The spot exchange rate is the current exchange rate, while the forward exchange rate is an exchange rate that is quoted and traded today but for delivery and payment on a specific future date.
In the retail currency exchange market, different buying and selling rates will be quoted by money dealers. Most trades are to or from the local currency. The buying rate is the rate at which money dealers will buy foreign currency, and the selling rate is the rate at which they will sell that currency. The quoted rates will incorporate an allowance for a dealer's margin (or profit) in trading, or else the margin may be recovered in the form of a commission or in some other way. Different rates may also be quoted for cash, a documentary transaction or for electronic transfers. The higher rate on documentary transactions has been justified as compensating for the additional time and cost of clearing the document. On the other hand, cash is available for resale immediately, but incurs security, storage, and transportation costs, and the cost of tying up capital in a stock of banknotes (bills).
The retail exchange market
Currency for international travel and cross-border payments is predominantly purchased from banks, foreign exchange brokerages and various forms of bureaux de change. These retail outlets source currency from the interbank markets, which are valued by the Bank for International Settlements at US$5.3 trillion per day. The purchase is made at the spot contract rate. Retail customers will be charged, in the form of commission or otherwise, to cover the provider's costs and generate a profit. One form of charge is the use of an exchange rate that is less favourable than the wholesale spot rate. The difference between retail buying and selling prices is referred to as the bid–ask spread.
Quotations
There is a market convention that rules the notation used to communicate the fixed and variable currencies in a quotation. For example, in a conversion from EUR to AUD, EUR is the fixed currency, AUD is the variable currency and the exchange rate indicates how many Australian dollars would be paid or received for 1 euro.
In some areas of Europe and in the retail market in the United Kingdom, EUR and GBP are reversed so that GBP is quoted as the fixed currency to the euro. In order to determine which is the fixed currency when neither currency is on the above list (i.e. both are "other"), market convention is to use the fixed currency which gives an exchange rate greater than 1.000. This reduces rounding issues and the need to use excessive numbers of decimal places. There are some exceptions to this rule: for example, the Japanese often quote their currency as the base to other currencies.
Quotation using a country's home currency as the price currency is known as direct quotation or price quotation (from that country's perspective) For example, = in the Eurozone and is used in most countries.
Quotation using a country's home currency as the unit currency (for example, = in the Eurozone) is known as indirect quotation or quantity quotation and is used in British newspapers; it is also common in Australia, New Zealand and the Eurozone.