Market dynamics

The breadth, depth, and liquidity of the market are truly impressive. It has been estimated that the world's most active exchange rates like EURUSD and USDJPY can change up to 18,000 times during a single day.
Somewhere on the planet, financial centers are open for business, and banks and other institutions are trading the dollar and other currencies, every hour of the day and night, aside from possible minor gaps on weekends. In financial centers around the world, business hours overlap; as some centers close, others open and begin to trade.
The foreign exchange market follows the sun around the earth. Each business day arrives first in the Asia-Pacific financial centers; first Wellington, New Zealand, then Sydney, Australia, followed by Tokyo, Hong Kong, and Singapore. A few hours later, while markets remain active in those Asian centers, trading begins in Bahrain and elsewhere in the Middle East. Later still, when it is late in the business day in Tokyo, markets in Europe open for business. Subsequently, when it is early afternoon in Europe, trading in New York and other U.S. centers starts. Finally, completing the circle, when it is middle or late afternoon in the United States, the next day has arrived in the Asia-Pacific area, the first markets there have opened, and the process begins again.
The graph underneath displays not only the currency trading time cycle but also the average 'depth' of trading at different times during the day in the various business hours.