Traders can earn money by using a meticulous trading strategy, many times with the help of bots, and by having continued and on time information about what's happening in the markets, with the assets, companies and so on.

The main basis for trading is to;

Never use all of your stack, let's say 25%
Buy low and Sell High. stipulate your selling position. sell between 12% to 15% profit
when buying, if the price falls down, either buy more and try to edge to sell at a higher point or sell it at max 10% loss.