What Is Foreign Exchange (Forex)?Foreign Exchange is the trading of one currency for another. For example, one can swap the U.S. dollar for the euro. Foreign exchange transactions can take place on the foreign exchange market, also known as the Foreign Exchange market. The forex market is the largest, most liquid market in the world, with trillions of dollars changing hands every day. There is no centralized location. Rather, the forex market is an electronic network of banks, brokers, institutions, and individual traders (mostly trading through brokers or banks). The market determines the value, also known as an exchange rate, of the majority of currencies. Foreign exchange can be as simple as changing one currency for another at a local bank. It can also involve trading currency on the foreign exchange market. For example, a trader is betting a central bank will ease or tighten monetary policy and that one currency will strengthen versus the other