The world's largest foreign exchange market is located in London.
Foreign exchange, or forex, is a global over-the-counter market where currencies are traded in pairs, such as the euro against the U.S. dollar. It has no single central exchange; instead, banks, dealers, companies, funds and other institutions trade through interconnected financial centres.
London became the leading centre partly because of its historical role in international finance and its convenient overlap with Asian and North American trading hours. The United Kingdom consistently accounts for the largest share of global foreign-exchange turnover, ahead of the United States, Singapore, Hong Kong and Japan.
A common mix-up is confusing the biggest market with the biggest national economy. New York is extremely important, and Tokyo and Singapore are major Asian hubs, but London remains the dominant trading centre. Forex trading is also nearly continuous on weekdays, moving from one regional session to the next.