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.

While major Cryptocurrencies were down from 4.5 - 5.5%, Bitcoin Cash dropped over 8.4%. 

Ahhhhhh...that feeling when #BCH is down further than the others on coinbase. #LTC #BTC #ETH pic.twitter.com/zDIU5IoaAU

The CTFC subpoenas were issued after several of the exchanges refused to voluntarily share trading data with the CME after being asked last December. Of note, the CFTC regulates the CTC. 

According to the WSJ, the CME, which launched bitcoin futures in December, asked the four exchanges to share reams of trading data after its first contract settled in January, people familiar with the matter said. But several of the exchanges declined to comply, arguing the request was intrusive. The exchanges ultimately provided some data, but only after CME limited its request to a few hours of activity, instead of a full day, and restricted to a few market participants, the people added.

What is curious, is that if there was indeed manipulation since the launch of bitcoin futures, it was to the downside, as the price of cryptos peaked around the time the crypto futures were launched, and are down well over 50% in the 6 months since.

Coinbase in particular has been under the watch government regulators. On February 23, Coinbase sent an official notice to around 13,000 customers to notify them they were legally required to turn over their information to the IRS. 

The IRS had initially asked Coinbase in July 2017 to hand over even more detailed information on every one of its then over 500,000 users in an attempt catch those cheating on their taxes. However, another court order in Nov. 2017 reduced this number to around 14,000 “high-transacting” users, which the platform now reports as 13,000, in what Coinbase calls a “partial, but still significant, victory for Coinbase and its customers.”

Coinbase...