If this year will be a tough year for cryptocurrencies, then maybe by next year, a reversion of trend may be possible in response to this year's almost all-year-long fluctuation now. From 2019 onwards, i believe bitcoin and the rest of cryptos will also respond well.
Yes this year is still hard for Bitcoin, and of course we can not predict what other year will be, , but I also hope that the next year will be much better for those.
I do not want to predict anything about the next year because I not believe in predictions. The reason is that all the previous year predictions became false and were against the actuality. No one can make predictions about the coming time. Some analysts predict according to their surveys and analysis, but nobody can say why most of the investors withdrew their money from bitcoin.