50k$ is so big for ending of this year but i think and expecting that bitcoin will raise 20k$ after end of this year bitcoins price now is so stable and no point if will increase lately.
Naturally, this price seems to all something impossible but I am sure it will be reached (no, not in 2018 but a bit later). However, we have to wait for it at least 2 or 3 years.
This is my vision as well that price is not impossible but it's impossible to reach in such a short amount of time, but give bitcoin two or three years and that price doesn't sound so crazy now, even in that time frame it is going to be difficult for bitcoin the reach that price but I really hope that at that time bitcoin is already in the middle of a new bull market and reaches a price at least close to that.