Let me ask you something, I’d like to know how you treat the money you use for gambling. Do you consider it an expense or an investment?
Gambling is a game of chance with its outcome dependent on luck. Let's be clear on that. So, having that in mind it won't be that wise to class any money one spends gambling as an investment. It's like banking on something that one can't really predict. That's not how investment works. I see whatever that's spent on gambling as expenses, and rightly so too.
So why we still think that trader is a profession? It is the same with gambling. He tries to predict result and get some profit with it. Of course, i`m talking about sport betting, it is predictable and we can calculate something. Not 100% of course, but it can be enough to get profit. Random games is only expense, even if we sometimes win.