You move from "gambling" to "investing" by analyzing the target company and coming up with your view of the correct price for the stock. You then compare this p

You move from "gambling" to "investing" by analyzing the target company and coming up with your view of the correct price for the stock. You then compare this price to the market price. If market price is lower, buy. Otherwise don't. This is basically the same way professional sports betting works. People involved collect information about the teams and try to understand how this information affects the outcome of the match. Once they have established their own view on the probabilities, they check the odds bookmaker if offering and calculate the expected outcome, i.e. how much money will this bet give me. If your calculations are right, then repeating this over and over again will lead to profitable betting in long term. In a sense the gambling/investing distinction is just in your own head. Maybe you are so bad at evaluation the companies that a coin toss would be better predictor for success than your Excel sheets.