Bitcoins won’t rise up than 50k USD.
The reasons for this is that, when it touches 50k USD, it will become very much expensive to buy for the crypto traders, so soon the transactions on BTC will be come down and as the demand of the BTC will be less, so price will gradually come down.
Is there a big difference between $40k or $50k for institutional investors? I don't think so, because they can afford to buy something at such a high price, which is not a big problem for them. If we take into account that we are just at the beginning of a real bull run, then $50k is really just maybe a small psychological limit that will be crossed quickly.
As for ATH for 2021, given the current situation I think it would be realistic to reach at least $100 000, although that seems like a very modest figure at the moment.