Trading characteristics
Most traded currencies[1]Currency distribution of reported FX market turnover
Rank
Currency
ISO 4217code
Symbol
% daily share(April 2004)
1
United States dollar
USD
$
88.7%
2
Eurozone euro
EUR
€
37.2%
3
Japanese yen
JPY
¥
20.3%
4
British pound sterling
GBP
£
16.9%
5
Swiss franc
CHF
Fr
6.1%
6
Australian dollar
AUD
$
5.5%
7
Canadian dollar
CAD
$
4.2%
8
Swedish krona
SEK
kr
2.3%
9
Hong Kong dollar
HKD
$
1.9%
10
Norwegian krone
NOK
kr
1.4%
Other
15.5%
Total
200%
There is no single unified foreign exchange market. Due to the over-the-counter (OTC) nature of currency markets, there are rather a number of interconnected marketplaces, where different currency instruments are traded. This implies that there is not a single dollar rate but rather a number of different rates (prices), depending on what bank or market maker is trading. In practice the rates are often very close, otherwise they could be exploited by arbitrageurs.
The main trading centers are in London, New York, Tokyo, and Singapore, but banks throughout the world participate. Currency trading happens continuously throughout the day; as the Asian trading session ends, the European session begins, followed by the US session and then back to the Asian session, excluding weekends.
There is little or no 'inside information' in the foreign exchange markets. Exchange rate fluctuations are usually caused by actual monetary flows as well as by expectations of changes in monetary flows caused by changes in GDP growth, inflation, interest rates, budget and trade deficits or surpluses, large cross-border M&A deals and other macroeconomic conditions. Major news is released publicly, often on scheduled dates, so many people have access to the same news at the same time. However, the large banks have an important advantage; they can see their customers' order flow.
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 ISO 4217 international three-letter code of the currency into which the price of one unit of XXX is expressed. For instance, EUR/USD is the price of the euro expressed in US dollars, as in 1 euro = 1.3045 dollar. Out of convention, the first currency in the pair, the base currency, was the stronger currency at the creation of the pair. The second currency, counter currency, was the weaker currency at the creation of the pair.
The factors affecting XXX will affect both XXX/YYY and XXX/ZZZ. This causes positive currency correlation between XXX/YYY and XXX/ZZZ.
On the spot market, according to the BIS study, the most heavily traded products were:
EUR/USD: 28 %
USD/JPY: 18 %
GBP/USD (also called sterling or cable): 14 %
and the US currency was involved in 88.7% of transactions, followed by the euro (37.2%), the yen (20.3%), and the sterling (16.9%) (see table). 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 far still largely dollar-centered. 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 interbank spot market.

Factors affecting currency trading
See also: Exchange rates
Although exchange rates are affected by many factors, in the end, currency prices are a result of supply and demand forces. The world's currency markets can be viewed as a huge melting pot: in a large and ever-changing mix of current events, supply and demand factors are constantly shifting, and the price of one currency in relation to another shifts accordingly. No other market encompasses (and distills) as much of what is going on in the world at any given time as foreign exchange.
Supply and demand for any given currency, and thus its value, are not influenced by any single element, but rather by several. These elements generally fall into three categories: economic factors, political conditions and market psychology.

[edit] Economic factors
These include economic policy, disseminated by government agencies and central banks, economic conditions, generally revealed through economic reports, and other economic indicators.
Economic policy comprises government fiscal policy (budget/spending practices) and monetary policy (the means by which a government's central bank influences the supply and "cost" of money, which is reflected by the level of interest rates).
Economic conditions include:
Government budget deficits or surpluses: The market usually reacts negatively to widening government budget deficits, and positively to narrowing budget deficits. The impact is reflected in the value of a country's currency.
Balance of trade levels and trends: The trade flow between countries illustrates the demand for goods and services, which in turn indicates demand for a country's currency to conduct trade. Surpluses and deficits in trade of goods and services reflect the competitiveness of a nation's economy. For example, trade deficits may have a negative impact on a nation's currency.
Inflation levels and trends: Typically, a currency will lose value if there is a high level of inflation in the country or if inflation levels are perceived to be rising. This is because inflation erodes purchasing power, thus demand, for that particular currency.
Economic growth and health: Reports such as gross domestic product (GDP), employment levels, retail sales, capacity utilization and others, detail the levels of a country's economic growth and health. Generally, the more healthy and robust a country's economy, the better its currency will perform, and the more demand for it there will be.

[edit] Political conditions
Internal, regional, and international political conditions and events can have a profound effect on currency markets.
For instance, political upheaval and instability can have a negative impact on a nation's economy. The rise of a political faction that is perceived to be fiscally responsible can have the opposite effect. Also, events in one country in a region may spur positive or negative interest in a neighboring country and, in the process, affect its currency.

[edit] Market psychology
Market psychology and trader perceptions influence the foreign exchange market in a variety of ways:
Flights to quality: Unsettling international events can lead to a "flight to quality," with investors seeking a "safe haven". There will be a greater demand, thus a higher price, for currencies perceived as stronger over their relatively weaker counterparts.
Long-term trends: Currency markets often move in visible long-term trends. Although currencies do not have an annual growing season like physical commodities, business cycles do make themselves felt. Cycle analysis looks at longer-term price trends that may rise from economic or political trends. [4]
"Buy the rumor, sell the fact:" This market truism can apply to many currency situations. It is the tendency for the price of a currency to reflect the impact of a particular action before it occurs and, when the anticipated event comes to pass, react in exactly the opposite direction. This may also be referred to as a market being "oversold" or "overbought".[5] To buy the rumor or sell the fact can also be an example of the cognitive bias known as anchoring, when investors focus too much on the relevance of outside events to currency prices.
Economic numbers: While economic numbers can certainly reflect economic policy, some reports and numbers take on a talisman-like effect: the number itself becomes important to market psychology and may have an immediate impact on short-term market moves. "What to watch" can change over time. In recent years, for example, money supply, employment, trade balance figures and inflation numbers have all taken turns in the spotlight.
Technical trading considerations: As in other markets, the accumulated price movements in a currency pair such as EUR/USD can form patterns that may be recognized and utilized by traders for the purpose of entering and exiting the market, leading to short-term fluctuations in price. Many traders study price charts in order to identify such patterns. [6]

Algorithmic trading in forex
Electronic trading is growing in the FX market, and algorithmic trading is becoming much more common. There is much confusion about the technique. According to financial consultancy Celent estimates, by 2008 up to 25% of all trades by volume will be executed using algorithm, up from about 18% in 2005.

Financial instruments
There are several types of financial instruments commonly used.
Spot: A spot transaction is a two-day delivery transaction, as opposed to the futures contracts, which are usually three months. This trade represents a “direct exchange” between two currencies, has the shortest time frame, involves cash rather than a contract; and interest is not included in the agreed-upon transaction. The data for this study come from the spot market. Spot has the largest share by volume in FX transactions among all instruments.
Forward transaction: One way to deal with the Forex risk is to engage in a forward transaction. In this transaction, money does not actually change hands until some agreed upon future date. A buyer and seller agree on an exchange rate for any date in the future, and the transaction occurs on that date, regardless of what the market rates are then. The duration of the trade can be a few days, months or years.
Futures: Foreign currency futures are forward transactions with standard contract sizes and maturity dates — for example, 500,000 British pounds for next November at an agreed rate. Futures are standardized and are usually traded on an exchange created for this purpose. The average contract length is roughly 3 months. Futures contracts are usually inclusive of any interest amounts.
Swap: The most common type of forward transaction is the currency swap. In a swap, two parties exchange currencies for a certain length of time and agree to reverse the transaction at a later date. These are not standardized contracts and are not traded through an exchange.
Options: A foreign exchange option (commonly shortened to just FX option) is a derivative where the owner has the right but not the obligation to exchange money denominated in one currency into another currency at a pre-agreed exchange rate on a specified date. The FX options market is the deepest, largest and most liquid market for options of any kind in the world.

Speculation
Controversy about currency speculators and their effect on currency devaluations and national economies recurs regularly. Nevertheless, many economists (e.g. Milton Friedman) have argued that speculators perform the important function of providing a market for hedgers and transferring risk from those people who don't wish to bear it, to those who do. Other economists (e.g. Joseph Stiglitz) however, may consider this argument to be based more on politics and a free market philosophy than on economics.
Large hedge funds and other well capitalized "position traders" are the main professional speculators.
Currency speculation is considered a highly suspect activity in many countries. While investment in traditional financial instruments like bonds or stocks often is considered to contribute positively to economic growth by providing capital, currency speculation does not, according to this view; it is simply gambling, that often interferes with economic policy. For example, in 1992, currency speculation forced the Central Bank of Sweden to raise interest rates for a few days to 150% per annum, and later to devalue the krona. Former Malaysian Prime Minister Mahathir Mohamad is one well known proponent of this view. He blamed the devaluation of the Malaysian ringgit in 1997 on George Soros and other speculators.[7]
Gregory Millman reports on an opposing view, comparing speculators to "vigilantes" who simply help "enforce" international agreements and anticipate the effects of basic economic "laws" in order to profit.
In this view, countries may develop unsustainable financial bubbles or otherwise mishandle their national economies, and forex speculators only made the inevitable collapse happen sooner. A relatively quick collapse might even be preferable to continued economic mishandling. Mahathir Mohamad and other critics of speculation are viewed as trying to deflect the blame from themselves for having caused the unsustainable economic conditions.