The price of bitcoin has fallen below $4,000 for the first time since September 26, 2017 and is now down 30 percent in the last 7 days alone.
The CBOE's website became unavailable just as it launched its first bitcoin futures contracts on Sunday.
Bitcoin prices managed to reach one week above $760 early on 14th December. During this seven-day period, these prices reached a 2016 high of $788.49.
