The foreign exchange market exists wherever one currency is traded for another. This is an international exchange market where simultaneous buying of one currency and selling of another is done. Currencies are traded in pairs, for example Euro/US Dollars (EUR/USD) or US Dollars/Japanese Yen (USD/JPY). It is by far the largest market in the world, in terms of cash value traded and includes trading between large banks, central banks, multinational corporations, governments and other financial market and institutions.

The foreign exchange market is unique because of its trading volume, the extreme liquidity of the market (i.e. price stability even with the fastest buying or selling), the large number and variety of traders in the market, its geographical dispersion, its long trading hours (24 hours a day ? except weekends) and the variety of factors that affect exchange rates.

The minimum trading size in this market is usually $1 million, with an overall trading volume of about $1.9 trillion per day worldwide. Buying and Selling of currencies is basically for two reasons. About 5% of daily turnover is from companies and governments that buy or sell products and services in a foreign country or must convert profits made in foreign currencies into their domestic currency. The other 95% is mostly for profit. In fact, this market has the potential to earn almost $100,000 with an initial capital of only $500!

The ten most active traders account for almost 73% of trading volume. These are Deutsche Bank (17%), UBS (12.5%), Citigroup (7.5%), HSBC (6.4%), Barclays (5.9%), Merrill Lynch (5.7%), J.P. Morgan Chase (5.3%), Goldman Sachs (4.4%), ABN AMRO (4.2%), Morgan Stanley (3.9%). These large international banks continually provide the market with both bid (buy) and ask (sell) prices. The bid/ask spread is the difference between the price at which a bank or market maker will sell ("ask", or "offer") and the price at which a market-maker will buy ("bid") from a wholesale customer. This spread is minimal for actively traded pairs of currencies, usually only 1-3 pips. One pip is the smallest measure of price move used in forex trading and refers to 1/10,000 of the bid/ask spread. For example, the bid/ask quote of EUR/USD might be 1.2200/1.2203 (i.e. 3 pips difference).

Although the banks get the least and most stable bid/ask spread they never offer the same rates to their customers, since their key purpose of participating in this market is for profit.

Currencies are traded against one another. Each pair of currencies thus constitutes an individual product and is traditionally noted XXX/YYY, where YYY is the international three-letter code of the currency into which the price of one unit of XXX currency is expressed. For instance, EUR/USD is the price of the euro expressed in US dollars, as in 1 euro = 1.2045 dollar. According to April 2004's BIS (Bank for International Settlement) study, the most heavily traded products were: EUR/USD (28 %), USD/JPY (17 %) GBP/USD (14 %). The US currency was involved in 89% of transactions, followed by the euro (37%), the yen (20%) and sterling (17%) - (Note that volume percentages should add up to 200% - 100% for all the sellers, and 100% for all the buyers). Although trading in the euro has grown considerably since the currency's creation in January 1999, the foreign exchange market is thus still largely dollar-centred. For instance, trading the euro versus a non-European currency ZZZ will usually involve two trades: EUR/USD and USD/ZZZ. The only exception to this is EUR/JPY, which is an established traded currency pair in the inter-bank market.

According to the BIS study, 53% of transactions were strictly inter-dealer (i.e. inter-bank), 33% involved a dealer (i.e. a bank) and a fund manager or some other non-bank financial institution, and only 14% were between a dealer and a non-financial company. The inter-bank market caters for both the majority of commercial turnover and large amounts of speculative trading every day. A large bank may trade billions of dollars daily. Some of this trading is undertaken on behalf of customers, but much is conducted by proprietary desks, trading for the bank's own account.

On the other hand, retail forex brokers handle a minute fraction of the total volume of the foreign exchange market, estimated at $25-50 billion daily, which is about 2% of the whole market. In the retail forex industry market makers more often than not run two separate trading desks- one that they use to actually trade foreign exchange (essentially serving as a proprietary trading desk or "non-dealing desk") and one that is set up for the expressed purpose of off-exchange trading with retail customers (called the "dealing desk" or "trading desk"). The dealing desk operates much like the currency exchange counter at a bank. Inter-bank exchange rates, those coming in from the inter-bank system and displayed at the non-dealing desk, are adjusted to incorporate spreads that safeguard the bank's (in this instance the market maker's) profit before they are displayed in the lobby (at the dealing desk) to the retail customer. Dealing desk pricing is, therefore, not a direct reflection of the currency exchange but artificial pricing created and controlled by the originating broker.

Forex Brokers tend to provide better exchange rates compared to the banks also trading in the forex market as well as companies such as Western Union or MoneyGram in order to keep up their competition against them. Hence dealing with specialist international forex brokering companies is a suitable way to transfer money overseas both in large and small amounts.