The FX Market
Exchange currencies by contracts.
The major pairs: EUR/USD, USD/CHF, EUR/JPY,...
Average daily currency trading volumes exceed $2 trillion per day. It's about 10 to 15 times the size of daily trading volume on all the world's stock markets.
FX Markets have different trading sessions as Asia-Pacific, European/London, and North America.
It's open 24 hours a day. It's close on from Friday afternoon to Sunday afternoon (EST).