eli5: How do stock traders know when to buy and sell, is it pure guessing or is there factors that affect it?

Question

eli5: How do stock traders know when to buy and sell, is it pure guessing or is there factors that affect it?

In: 1

Answer 1

Mostly guessing. A lot will claim some plan or algorithm or insight. But for every buy there is a equal and opposite person deciding to sell. It’s a zero sum game.