The forex market is the largest market in the world. According to the Triennial Central Bank Survey conducted by the Bank for International Settlements, the average daily trading volume reached $1.9 trillion in 2004. This huge trading volume provides the forex market with excellent liquidity, which benefits a large number of traders that invest there. The growth of the forex market has been spurred by the development of electronic trading networks and the increase in globalization.

Specifically, the forex market focuses on the trade of currencies by both large investment banks and individuals around the world. All trading is done over-the-counter, which adds to the market's liquidity, allowing trades to be made 24 hours a day. Trading can be done in nearly all currencies. However, a small group known as the 'majors' is used in most trades. These currencies are the U.S. dollar, the euro, the British pound, the Japanese yen, the Swiss franc, the Canadian dollar, and the Australian dollar. All currencies are quoted in currency pairs.

When a trade is made in forex, it has two sides - someone is buying one currency in the pair, while another individual is selling the other. Although the positions traded in forex are often in excess of 100,000 currency units, only a fraction of the total position comes from the investor. The remainder is provided by a broker, which offers the leverage needed to make the trade.

Traders look to make a profit by betting that a currency's value will either appreciate or depreciate against another currency. For example, assume that you purchase US$100,000 by selling 80,000 euros. In this case, you are betting that the value of the dollar will increase against the euro. If your bet is correct and the value of the dollar increases, you will make a profit. In order to collect this profit, you will have to close your position. To do this, you must sell the US$100,000, in which case you will receive more than 80,000 euros in return.

Traders are not required to settle their positions on the delivery date, which usually arises two business days after the position is opened. Traders can roll over their positions to the next available delivery date. However, if a trader takes this route, he or she is left open to incurring a charge that can arise depending on his or her position and the difference between the interest rates on the two currencies in the pair.