Well, you are supposed to use what you can afford to lose while trading. You cannot just throw all your reserves into a particular coin as well. Learn to share your portfolio among several coins, not more than 3 at a time. Most times I trade Icx, Veil and Neo. This helps you have time to research properly on them and reduces your risks of making losses. Also there's no particular trading rule. Once you have done your research on coins with great community backing them up and have a potential to be massive, you should be able to invest and trade such coins.