The work below was recently done by a good friend and ex colleague of mine Dr Andrew Jim. It was completed during the most recent sell-off in Bitcoin, the result of yet another China ban. Using R programming language Andrew took the top 10 historical BTC max Drawdowns looking at the time it takes (in days) from peak equity to trough and recovery back to its previous peak. (He uses Median instead of average to filter out the massive outliers in 2011 & 2013). So the last dump ranked #8… -34% from the peak.. On Sept 18 Andrew predicted that given the median of 37 days recovery from trough to another peak it might take another ~30+ days for BTC to regain 5000….it actually only took 25 days!