The forex market is the largest financial market in the world. Trading in the forex is not done at one central location but is conducted between participants in various markets around the world.
The market is open 24 hours a day in different parts of the world, from 5 p.m. EST (9PM GMT) - on Sunday until 4 p.m. EST (9 PM GMT) on Friday. At any point in time, there is at least one market open and there are few hours of overlap between one region's market closing and another opening. The international scope of currency trading means that there are always traders across the globe who are making and meeting demands for a particular currency.