100 USD is definitely enough to start trading if you aren't unrealistic in your goals. For example, expecting to make lots of money from 100 USD worth of any currency simply will not happen in the short term. You will need to be patient and disciplined in order to find out if you really can make gains in the market. As you start to make small % gains you can pour more money and go from there. It is usually tough when starting out, so you cannot lose hope and determination. I hope you find trading success!