when i saw the price i thought the price wouldn't reach $ 50k. maybe the price will come back $ 15k. if you look at ATH 2017-2018 
That is probable but I don't think it will be.
With the price reaching that kind of height, if the price went down lower than $20K, for sure people would take it as an opportunity. I don't think it would even reach that kind of price lower than $20K. I am seeing the price in the near future at $50K and it might reach higher considering the demand and the adoption that would happen.