Forex, also known as a foreign a exchange, FX or currency trading – is a decentralized global market where all the world's currencies are traded. The Forex market is the largest and most liquid market in the world with an average daily trading volume exceeding $5 trillion. All forex trades include two currencies that allow you to predict the value of a currency against another. EUR/USD is the most traded currency pair in the world. For example, if you think the EUR is going to increase in value against the USD, you could place a trade to buy the EUR/USD currency pair. If the Euro rises, you would make a profit; if it drops you would incur a loss. Vice versa, if you thought the Euro was going to decrease in value, you could place a trade that would benefit from that price movement.