The foreign exchange
The foreign exchange (currency or forex or FX) market exists wherever one currency is traded for another.
It is by far the largest financial market in the world, and includes trading between large banks, central banks, currency speculators, multinational corporations, governments, and other financial markets and institutions.
The average daily trade in the global forex and related markets currently is over US$ 3 trillion. Retail traders (individuals) are a small fraction of this market and may only participate indirectly through brokers or banks, and are subject to forex scams.
Unlike a stock market, where all participants have access to the same prices, the forex market is divided into levels of access. At the top is the inter-bank market, which is made up of the largest investment banking firms. Within the inter-bank market, spreads, which are the difference between the bid and ask prices, are razor sharp and usually unavailable, and not known to players outside the inner circle.