I believe that the market is cyclical, so after rapid growth it has to restore during next 2-3 years. It was so in 2014-2017 years, and the same situation I think would be in 2017-2020 period. Of course, we will see some price spikes (I think, by the end of the year) but the price of BTC will not rise to its maximum in 2017. Also I believe that BTC would cost at least 50000$ in 2021. This is not only my opinion, but the forecast of analytics which I believe.