NEW YORK/LONDON: Bitcoin plunged by 30 per cent to below US$12,000 on Friday as investors dumped the cryptocurrency after its sharp rise to a peak close to US$20,000 prompted warnings by experts of a bubble.

After falling to as low as US$11,159, it recouped some losses to trade above US$14,000 on the Bitstamp platform, down 9 per cent on the day. It is down around 25 per cent this week, its largest weekly loss since April 2013.

It capped a brutal week that had been touted as a new era of mainstream trading for the digital currency when bitcoin futures debuted on CME Group Inc, the world's largest derivatives market on Sunday.

Friday's fall bled into the US stock market, where shares of companies that have lashed their fortunes to bitcoin or blockchain - its underlying technology - took a knock. Long Blockchain Corp, Overstock.com Inc, Riot Blockchain Inc and Marathon Patent Group Inc lost between 2 per cent and 15 per cent.

The biggest and best-known cryptocurrency has risen around twentyfold since the start of the year, climbing from less than US$1,000 to as high as US$19,666 on the Luxembourg-based Bitstamp exchange on Sunday and to over US$20,000 on other exchanges. But it has fallen each day since.

In the futures market, bitcoin one-month futures on Cboe Global Markets were earlier halted due to the steep price drop, while those trading on the CME hit the limit down threshold.

"The crypto markets have experienced several flash crashes over the past few years but we do believe there has been some overvaluation in the market, particularly over recent months," said Jamie Burke, chief executive officer at venture capital firm Outlier Ventures.

"It's much more likely this is a natural correction following over-exuberant market sentiment." -- REUTERS