Simple but good analysis IMHO. $50k isn't that far from where we are today. The fact that it had peaked at $42k, and if there will be another bounce back, it will get close to the target price that you've given.
@iamwithyou, do you plan to sell if bitcoin gets to $50k or close to it?
I am not selling bitcoin no matter what. I have learnt from my past mistakes. I bought at 21000$, may be at 50000$ I will sell 20% but I am not going out.
I agree that this is a good decision, selling right now would be a bad decision because we are not going down right now, we are still doing good. Normally people ask if they should sell without giving numbers so I can't talk about it that much, but since you said that you bought at 21k I can talk about that.
If you have bought at 21k that means until it is 21k you are not going to lose money, which means you could consider that as a place where you could end up still selling. So do this, wait until it goes back to 21k, and sell it there if you have, if the price never reaches there, and goes to 100k+ or something, you could get out and use that money.
Secondly, if you have invested let's say 10k dollars, and your bitcoin worths 30k one day, sell the 10k and keep the 20k and you will be capable of waiting forever because all of that is profit and none of that is your money.