Bitcoin and other cryptocurrencies flash-crashed Saturday night, one day after the US Commodity Future Trading Commission (CFTC) sent subpoenas four cryptocurrency exchanges in an ongoing probe into bitcoin manipulation that began in late July - following the launch of bitcoin futures on the CME, according to the Wall Street Journal. 

CME's bitcoin futures derive their final value from prices at four bitcoin exchanges: Bitstamp, Coinbase, itBit and Kraken. Manipulative trading in those markets could skew the price of bitcoin futures that the government directly regulates.

In delay reaction, Bitcoin fell as much as $433 or 5.6% in Saturday night trading, with some noting that the flash crash happened shortly after a 90th ranked crypto exchange, Coinrail, had suffered a "cyber intrusion", and was likely the more relevant catalyst for the crypto price drop.