Theoretically, any country with its own currency can enter the platform for foreign exchange trading, but some countries' currencies do not support foreign exchange trading for different reasons. There are about 80 currency pairs supported by general platforms, such as euro against dollar, dollar against yen and pound against yen. In addition to currencies, precious metals and indexes also support trading, such as gold, silver, crude oil, natural gas, Hang Seng Index and Dow Jones.