MATH. Do your research. Learn about the market. Learn what the overall market does, and when. Try to find out why—not necessarily why it went up or down on a given date, but what powers the market to begin with.
Ever felt overwhelmed by some decision, and just picked an option so you didn't have to think about it anymore?It can be easy to get lost in numbers. And when your head is swimming, you won't make the best decisions!
It helps to see this kind of junk displayed in a graph. As hard as it can be to imagine how compound interest works, graphs like this can make it easy to understand!