Cryptocurrency

There's already 18 million in circulation, so there's only three million left to be mined. What happens when the last three million are sort of brought to surface? If we have a limited supply and still a lot of demand, then wouldn't that cause prices to increase? But on flipside, what if there's no more demand and it's all done, and people see all of it being mine as ok here's a thing? The thing with crypto, its very gray, like there's a lot of things that you need to think about and do your own research on. And at the end of the day, just like stocks, i i'm looking into what stock is right for