Foreign exchange transactions carry a high degree of risk and any transaction involving currencies is exposed to, among other things, changes in a country's political condition, economic climate, acts of nature - all of which may substantially affect the price or availability of a given currency.
Speculative trading in the foreign exchange market is a challenging prospect with above average risk. You must therefore carefully consider your investment objectives, level of experience and appetite for such risk prior to entering this market. Most importantly, do not invest money that you are not in a position to lose.
In addition, trading on a margin basis means that any market movement will have a proportionate effect on your deposited funds. This can work for you as well as against you. The possibility exists that you could sustain a total loss of initial margin funds.