To be fair, it is very likely the downtrend has indeed finished. All signs point to it being finished and Bitcoin currently being in the beginning of its consolidation period in which it starts its turnaround. Look for the slow uptrend to begin before the end of the year. 2019 will be the slow uptrend back to $20k, 2020 will be the next boom.
Finished and entirely spent could take a long time. Certainly we can say the rate of change has slowed quite alot. to the point BTC has held quite a stable range for months, it might move more over the next six months but I'm not sure I expect an actual reliable uptrend in 2019