There are three main centers of trading, which handle the majority of all FX transactions – United Kingdom, United States and Japan.
Transactions in Singapore, Switzerland, Hong Kong, Germany, France and Australia account for most of the remaining transactions in the market. Trading goes on 24 hours a day. The London market opens when the Japanese and Hong Kong markets are about to close. While the London market is in its half-day, the New York market opens. San Francisco market opens after trading in London get over. Japan resumes trading when San Francisco market closes down.