Foreign exchange market is the oldest market in the world. It is also seen to be the largest one. Forex is also the largest market with highest liquidity. This is an interbank market carrying out spot (or cash) transactions. The currency futures market, to be compared with Forex is traded only 1% as much.
This does not have any exchange center unlike the stock market. Forex trading seem to go after the sun around the world, from banks of the United States to other parts of the world like Australia, New Zealand, the Far East or Europe and back to the US some time later.
