|Rank||Currency||ISO 4217 Code||Symbol|
|1||United States dollar||USD||$|
|4||British pound sterling||GBP||£|
The main trading centers are in London, New York, and Tokyo, but banks throughout the world participate. As the Asian trading session ends, the European session begins, then the US session, and then the Asian begin in their turns. Traders can react to news when it breaks, rather than waiting for the market to open.
There is little or no 'inside information' in the foreign exchange markets. Exchange rate fluctuations are usually caused by actual monetary flows as well as by expectations of changes in monetary flows caused by changes in GDP growth, inflation, interest rates, budget and trade deficits or surpluses, and other macroeconomic conditions. Major news is released publicly, often on scheduled dates, so many people have access to the same news at the same time.
Currencies are traded against one another. Each pair of currencies thus constitutes an individual product and is traditionally noted XXX/YYY, where YYY is the ISO 4217 international three-letter code of the currency into which the price of one unit of XXX currency is expressed. For instance, EUR/USD is the price of the euro expressed in US dollars, as in 1 euro = 1.2045 dollar.
On the spot market, according to the BIS study, the most heavily traded products were:
- EUR/USD - 28 %
- USD/JPY - 17 %
- GBP/USD (also called cable) - 14 %
and the US currency was involved in 89% of transactions, followed by the euro (37%), the yen (20%) and sterling (17%). (Note that volume percentages should add up to 200% - 100% for all the sellers, and 100% for all the buyers). Although trading in the euro has grown considerably since the currency's creation in January 1999, the foreign exchange market is thus still largely dollar-centered. For instance, trading the euro versus a non-European currency ZZZ will usually involve two trades: EUR/USD and USD/ZZZ. The only exception to this is EUR/JPY, which is an established traded currency pair in the interbank spot market.