The foreign exchange market (forex, FX, or currency market) is a global decentralized market for the trading of currencies.This includes all aspects of buying, selling and exchanging currencies at current or determined prices.oreign exchange fixing is the daily monetary exchange rate fixed by the national bank of each country. The idea is that central banks use the fixing time and exchange rate to evaluate behavior of their currency. Fixing exchange rates reflects the real value of equilibrium in the market.