To make profitable with trading with simple choose buy and selling on good moment, many trader always late for buying some coin after break out to higher price and looks late when buying, but always early for selling their assets before price most expensive. Maybe have control when good moment to buy or sell coin.
It is not that simple to make a good timing in buying and selling because we cannot say if the coin is now on the top or below it's value. It is why trading is a little the same as gambling because it's all about chances. But if you can control your emotions and can properly manage your portfolios, you can earn good profit in trading.