Can we predict a crypto crash?

Crypto markets are no stranger to volatility however this past week has been particularly painful. The total market capacity of all cryptocurrencies fell from $740 billion to $420 billion in just four days, a brutal drop of over 40%. At the time of writing markets appear to be showing signs of recovery and are on the way back up again with over a hundred billion dollars added back since yesterday.
Speculation on the cause of the crash is rife but it would be more pertinent to simply look at hist