I think it will break through $20,000 at the end of 2018 and should stay above $50,000 in 2019.
It really depends, that's a huge expectation in 2019, remember how it gets stronger from time to time not just a year, but uptrend was just in a year, however if it comes up to 20k above, maybe the stable price if going to fluctuate in a certain time would stay lesser 20 or greater than 20k but 50k is kind of impossible in a short time.