How do stock traders determine the price of a stock within the course of hours, resulting in them purchasing and selling a stock in the same day?

I've seen people who purchase and sell stocks the same day, how do they do that? How do they gather information at such a limited time and still manage to gain profit?

Submitted January 31, 2018 at 06:25AM by shaansmwl77 http://ift.tt/2FyPSaS