Firstly I would pick a beginning point to define the start of the bull run, termed 'Estimated Start' in the above chart.
I would then plot the % increase with the corresponding duration for the short and long term bull runs we previously saw.
Short term: +1727% 89days
Long term: +1412% 152days
From these indicators we extracted from the first two bull runs we can see that at the 'Current Period' the real life (current data at that time for hypothetical sake) the indicators are no where near the actual trends expected.
This is quite possibly because its a non-linear relationship, so if we picked a start and adjusted the formula to suit the 'Current Period' this would allow us to calibrate our prediction. This is better using a non-linear power formula derived in say, Excel.
Looking at the difference straight away, we could possibly adjust the days and estimate how far into the run the bull has ran however this becomes more of a guessing game if we go down this route.
The next stage will be to develop a non-linear equation in excel and apply this to the analysis.