There are two reasons to buy and sell currencies. 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.
Secondly for speculative investment purposes. We believe the best trading opportunities are with the most commonly traded (and therefore most liquid) currencies, called "the Majors and minor crosses." Today, more than 85% of all daily transactions involve trading of the Majors, which include the US Dollar, Japanese Yen, Euro, British Pound, Swiss Franc, Canadian Dollar and Australian Dollar.
A true 24-hour market from Sunday 5:00 PM ET to Friday 5:00PM ET, Forex trading begins each day in Sydney, and moves around the globe as the business day begins in each financial center, first to Tokyo, London, and New York. Unlike any other financial market, investors can respond to currency fluctuations caused by economic, social and political events at the time they occur - day or night.
The FX market is considered an Over The Counter (OTC) or 'inter bank/interdealer' market, due to the fact that transactions are conducted between two counterparts over the telephone or via an electronic network. Trading is not centralized on an exchange, as with the stock and futures markets.