There are millions of Satoshi in one Bitcoin and are in bits so even if the total 21 million Bitcoinhase been mined, the total buts will only increase in price which gives Bitcoin an infinite total supply. But you should also understand that Bitcoin, if the demand increase so the scarcity will inflate the price.
This is where the laws of economics apply. with the increasing scarcity of bitcoins to be traded while demand increases, it will further increase the price, and of course this limited supply I think will only affect the price, and of course crypto currency is not only bitcoin. and of course if developments are in accordance with our vision for the future, then we are very suitable for investing, as many people are doing today.
It’s not always like that though. I mean for bitcoin it has been like that and it will stay like that for sure, but not everything in life. Sometimes, when there is a product that is debatable to be a valuable thing, and then some hardcore collectionists end up getting most of it, the remainder are not valuable because nobody wants it, and that’s when the price goes down a lot.
Bitcoin is not like that though, it is definitely something we all like, and will continue to like, and that is why it’s one of the best things ever for us. All in all, I have to say that the limited supply of bitcoin makes it the good thing, because printing more and more doesn't work, we have seen that in fiat.