The first thing you notice when you look at the monthly chart is that every bull run took longer to reach its high and the percentage increase is smaller compared to the previous ones. Also, the bear markets became longer. So, there is a clear deceleration of the momentum and the scenario in which BTC reaches 100k is quite unlikely to happen.
Based on the relationships between the distance in time and price of each bull run and its correction, we can make the following assumptions about the 4th bull run if there will be one:
-> it could start around Aug 2019
-> it will last for at least 33 months
-> the top could be hit after at least 24 months from the halving
-> the maximum percentage increase from the low of the current bear market (TBD) to the new ATH is 2750%
-> highly unlikely for the new ATH to be above 70k.