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 $6.5 trillion. In forex, a currency pair is the value of one currency (the base currency) in terms of the other (the counter currency). A currency's value is based on the strength of an economy, political stability, interest rate, inflation, productivity, trade balance and risk.