I'm not sure this can be classified as 'good news'. I mean, if you "lose" 850,000 bitcoins, and then suddenly "find" 200,000 bitcoins in the cushions of the couch, that still makes you a shitty bank.

TOKYO — 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.