any exchange you will lose will charge you like 2-3 dollars just to deposit and withdraw your funds, so that's about six dollars in total, which means if you invest hundred dollars you already made a loss of 6% before you even started trading. That's quite big and that's the reason as well why you shouldn't invest such low amounts when trying to invest or trade. Trading always takes a bit more guts in order to make some profit, but the most simple thing you can do is to hold the coins you are interested in and decide not to trade at all. Many are getting rekt by trading and starting at low amounts such as 100, it's better if you're new and a noob (to learn) but eventually you'll end up putting more money without even noticing. You can try liqui.io, which is kinda cool and has a lot of coins and low fees.