How can topics question be answered, when everyday altcoin appear and disapper? There is no exact number for that. Everything is in demand hands and in the hand of whale market players. Because they can drown and send to the sky. I am just sure that top20 from coinmarketcap will stay and even this is a discussible prediction.
Yeah we cannot define how much because there are no integrated website or apps that could count all of them even the big platform like coin marketcap is still not covers all of cryptocurrency circulating in the internet.
So we could not answer how many, but the most important thing the volume and the market cap of all cryptocurreny overall must be increase so we will see a healthy market in the next following years
It is more about how many of them will finish in positive while others in negative. When you look at year to date of many coins you will see that they are in big big profit, even if there is a huge drop in the middle, the increase at the start of the year made it possible for it to be super high even after that drop. Like for example, bitcoin was around late 20's and low 30's at the start and it is much higher than that even though it has managed to drop from 64k dollars.
This is why I honestly believe that there is a good chance some of the coins may end up with still a profit but a negative all around because it is still dropping. So, we need to check the average how much coins increased, what bitcoin did, and then compare it with others. If the crypto world is 50% up and a coin is only 5% up that is not good neither. Those type of things calculated with data and can be used as proof for the result of this question.