We must understand that short-term profits and losses may involve some luck factors, but what can bring you long-term stable profits is definitely a reliable system. Without a set system, these 'random gains' earned through luck are not replicable and will eventually be lost back.

In other words, you only need to and can earn money within the system, because it is the part that matches your level of understanding. At the same time, your system not only helps you make money but also helps you keep the money you have earned.