Bitcoin Down Sharply

Bitcoin plunged at the end of a rocky week, taking the digital currency below $12,000 U.S. and down more than 40% from its record high hit Sunday.

Bitcoin had rallied to a record high above $19,800 on Sunday and was trading near $15,500 for much of Thursday New York time, according to Coinbase. But an afternoon selloff accelerated into the night, and bitcoin dropped more than 30% Friday morning to $10,770 on the exchange.

With the decline, bitcoin has now fallen 40% in just five days and lost about $7,000.

Bitcoin futures also tumbled Friday. The CME bitcoin futures expiring in January, which launched Sunday, fell nearly 20 percent to $12,265 in morning trading. The Cboe bitcoin futures contract, which launched on Dec. 10, fell 23% to $11,750.

CME sent a notice saying the futures market was open and at limit. A futures trader confirmed to media outlets that trading appeared to be halted.

Coinbase is the leading U.S. platform for buying and selling major digital currencies, and also operates an exchange for institutional investors called GDAX.