Major bitcoin exchange Mt. Gox said it had found nearly a quarter of the bitcoins it previously said were lost, raising questions about how much of the missing total could eventually be recovered.
Mt. Gox Chief Executive Mark Karpelès said in a document released Thursday that the firm had found 200,000 bitcoins in a wallet — a digital file used to store bitcoin addresses and from which transactions can be done — that the company no longer uses. That brought the number of bitcoins still missing to roughly 650,000 from about 850,000.
“We believed there were no bitcoins left in old wallets, but found 199,999.99 bitcoins on March 7,” Mr. Karpeles said in the document released on Thursday.
How much of a role hacking played in the loss of the virtual currency from what was once the world’s biggest bitcoin exchange remains unclear. Mt. Gox never specified if all of the missing coins were taken by hackers.
When Mt. Gox filed for court protection in Japan on Feb. 28, Karpeles said a technical issue that enabled users to make fraudulent withdrawals was possibly behind the loss. The 850,000 missing bitcoins announced at the time represented roughly 7% of all bitcoins in circulation, and were worth more than $470 million at market prices at the time.