Truly to say, 100$ is not so big amount to trade in forex, but it is enough for them who are new in forex. Because forex is a very risky business and facing loss is very common here. If a trader join forex newly, then he will suffer some day for lack of proper knowledge and experience. And though this business is so risky, he may face loss any time. And i think it is so unsafe to invest much without any clear understanding about forex.