Forex, also known as foreign exchange, FX or currency trading, is a decentralized global market where all the world's currencies trade. The forex market is the largest, most liquid market in the world with an average daily trading volume exceeding $5 trillion. There is no central exchange as it trades over the counter. Forex trading allows you to buy and sell currencies, similar to stock trading except you can do it 24 hours a day, five days a week, you have access to margin trading, and you gain exposure to international markets. For a more in-depth introduction to the forex market.