Bitcoin spiked in value on Wednesday to a two-week high.

The world's best-known cryptocurrency surged from $6,466.50 at around midnight to $6,858.61 at around 1 a.m. London time, according to data from industry website CoinDesk.

It was the first time bitcoin has been above the $6,800 level since August 7. The reason for the sudden jump in the virtual currency's value was not immediately clear. The cryptocurrency softened slightly to $6,663.96 by around 2 p.m. London time Wednesday, up 2.87 percent in the last 24 hours.

Bitcoin is still down 66 percent from a record price near $20,000 it set in December last year.

Last week, bitcoin and its second and third-largest counterparts, ether and XRP, fell sharply. Analysts at the time said the rout was driven by an SEC (Securities and Exchange Commission) decision to postpone a decision on a proposed bitcoin ETF (exchange-traded fund).

Ether, the digital token of the Ethereum blockchain, was up 1.44 percent at a price of $286 at 2 p.m. London time, while XRP, which is associated with blockchain firm Ripple, was up 1.78 percent at a price of 34 cents, according to CoinDesk.

Separately on Wednesday, cryptocurrency trading platform BitMEX said it suffered a DDoS (distributed denial-of-service) attack, where hackers force a site offline. Earlier during the day, the firm said it was set to undergo "scheduled maintenance." Some media outlets reported the shutdown could have been behind the price spike for bitcoin.

Tweet