Cryptocurrency prices jumped on Thursday, led by a 10 percent surge in bitcoin to two-week highs, though analysts said they were unsure of what had triggered the spike.
On the Luxembourg-based Bitstamp exchange, bitcoin spiked as much as 14 percent at one point in mid-morning European trading and by 1225 GMT was up 10.3 percent at $7,657, its highest level since March 28.
Other cryptocurrencies like Ethereum and Ripple also rose sharply.
Two people active in the cryptocurrency market said the biggest moves in bitcoin had occurred on the Bitfinex exchange before spreading to other trading platforms, but they were struggling to see what had caused the jump.
Cryptocurrency prices had sagged in recent weeks, with price volatility also down.