Coincheck, Japan´s second largest cryptocurrency exchange, has suddenly stopped yen withdrawals, casting a pall over crypto markets.
Bitcoin traded just over 6% lower as at 1150 GMT on Friday. Ripple, meanwhile, was some 12% lower.
“All withdrawals from the platform are currently restricted, including JPY. Thank you for your understanding. We are doing our utmost to resume normal operations as soon as possible,” said a blog post from Coincheck.
The halt to yen withdrawals came after the exchange ceased trading in cryptocurrency NEM and all other cryptos except for bitcoin.
Coincheck handles just over 10% of all trading in bitcoin, with strong appetite for cryptocurrency from Japanese investors oft cited for the rapid rise in cryptos during 2017.
Sentiment in bitcoin and other major cryptos was also hit on Friday after speakers at the World Economic Forum at Davos expressed caution over the sharp rise in crypto values.
There are continuing worries over the prospect of regulatory intervention in crypto trading around the world.
“There’s undoubtedly growing interest among global policymakers on how to deal with cryptocurrencies. Japan’s approach would be to think about how to curb excesses without discouraging innovation,” Hiromi Yamaoka, head of the Japanese central bank’s division on payment and settlement systems.