Of course, we can’t trade currencies without knowing about them. There are a large number of currencies that traders can choose from for establishing their trades and portfolios, but most currency traders will concentrate on a few of the more widely traded, and liquid pairs such as the EUR/USD, GBP/JPY, or USD/CHF, which are all currencies of major powers. It is possible to divide currencies into many different groups based on the criteria chosen, but in general currency account position and interest rate policies of central banks are the most important values for classifying them.

If we try to divide currencies on the basis of financial soundness and economic policies, the following is one plausible categorization.

These are the currencies of nations which have a dominant role in global economic transactions. The European Union, Japan, the United States are the important powers the currencies of which fill the coffers of central banks around the world. Among those, the role of the Japanese Yen as a reserve currency has been diminishing since the 90’s, while that of the Euro has been increasing continuously since the launch of the currency. Among all those changes however, the US Dollar has remained as the one major currency that has the greatest preponderance over everything else in central bank currency allocations. With about two thirds of global forex reserves denominated in the dollar, the USD is the reserve currency of the world.

For traders, an important rule of thumb is that reserve currencies as a group tend to depreciate in times of boom, and to appreciate at times of economic trouble. This is a generalization; needless to say there is a degree of variation among the behavior of different currencies, but due to the financial structure of the global economy, economic activity usually leads to abundant supply of reserve currencies during robust economic growth.

Currencies such as the Australian and Canadian Dollars, the Brazilian Real, the South African Rand, or the Russian Ruble, which are the monetary units of commodity exporting nations, are called commodity currencies. There’s a great degree of diversity among commodity currencies in terms of trade balance or economic sophistication. However, due to the large currency inflows generated by proceeds from the sales of commodities, the value of these currencies is strongly dependent on the buoyancy of global commodity market.

Currencies of nations like Singapore, Japan, China, with large forex reserves accumulated through exports, are called exporter currencies. The value of these currencies is related strongly to the health of the global economy. As they depend on foreigners for economic buoyancy, any disturbance to the health of the global financial system can have outsized consequences for these nations. Nonetheless, due to their large forex reserves they are well-placed to withstand the impact of any economic shock better than most of their peers.

These may also belong to any of the other categories. High-risk currencies are the currencies of nations with high deficits (budget or trade), and high interest rates. Examples are Romanian Leu, currencies of Baltic nations, or Turkey. These currencies appreciate at times of boom, as capital from developed economies is directed to their assets, and depreciate during recessions and crises, as global capital discards risky assets.

Although the descriptions above may sound simple and brief, they already contain much of the basic concepts that are important for currency traders. The key to a successful trading career is carefully evaluating the widely available data, and establishing a disciplined and simple strategy which can be used to exploit the information for profit.