Within the context of the global market, the foreign exchange markets in London, New York, Sydney, and Tokyo are regarded as the four most important of their kind. Forex traders usually memorise their trading hours, paying special attention to the times of day when two exchanges overlap.
When multiple markets are active at the same time, the trading volume and volatility of the market increase. The degree to which the value of a share or currency fluctuates over time is referred to as volatility. Forex traders may come to believe that volatility works in their favour.

The four largest foreign exchange (forex) markets by trading volume are located in London, New York, Tokyo, and Singapore. London is the world’s largest forex hub, accounting for nearly 40% of global forex transactions, thanks to its strategic location between Asian and American markets. New York ranks second, handling about 20% of forex trades, driven by the U.S. dollar’s dominance and Wall Street’s influence. Tokyo is Asia’s leading forex centre, contributing around 6% of global volume, with heavy participation from institutional investors and the Bank of Japan. Singapore, a key financial hub, follows closely with 5% of forex trades, benefiting from its strong regulatory framework and proximity to emerging Asian markets. Together, these markets facilitate trillions in daily transactions, shaping global currency valuations and liquidity.