Forex (FX) is a shortened form of the words foreign [currency] and exchange. Foreign exchange is the process of changing one currency into another for various reasons, usually for commerce, trading, or tourism. The market is open 24 hours a day, five and a half days a week. Currencies are traded worldwide in the major financial centers of Frankfurt, Hong Kong, London, New York, Paris, Singapore, Sydney, Tokyo, and Zurich—across almost every time zone.