I find it significant that just a couple weeks before the crash, futures trading in BTC began. Derivatives are used to control markets, as we see in precious metals.
It is also very significant that during the crash there were no inflows to metals, RE, other assets, including cryptos, which also crashed, or even cash.
The only explanation is that money flowed into the dark pools. If this crash is a model for the ongoing dissolution of the markets, we can expect black markets to overtly control the world financially.