it is called speculation, not gambling. One of the big differences is that in gambling you do not have an advantage over the casino, they have the edge on you. In speculation you are taking an educated risk that something will happen based on study and investigation. For instance I might look into an alt coin and see that they have an actual  business that is making money and has investors that are big players in startups, so I say that I believe this will be a winner over the long run. So I put say $500 into this idea over time, if I do this with say 10 coins that I think will be winners over the long term. I am creating a portfolio of coins I believe will be good investments over the long run. I don't need them all to be big winners, but if just a few are and produce large returns my speculation will pay off big time.