TOKYO–Mark Karpeles, chief executive of the bankrupt Bitcoin exchange Mt. Gox, confirmed yesterday that he had found 200,000 of the 750,000 Bitcoins that mysteriously disappeared last month.

“I could have sworn I’d looked in that drawer, like, ten times already,” said Karpeles at a press conference here. “But somehow they were right there, next to a pile of old batteries.”

Karpeles’ mother, Gladys, interrupted the press conference at this point to observe that her son was sometimes a “knucklehead” and that she wouldn’t be surprised if the rest of the Bitcoins were “down in the basement with his old Dungeons and Dragons cards.”

“Mom, please, those cards are from Magic: the Gathering, and they’re really valuable,” said Karpeles. “Please stop embarrassing me.”

Rival Bitcoin exchanges cited the discovery of further proof that Mt. Gox had been run in an amateur fashion. “Nothing like our fully professional operation here,” said David Dryden, CEO of BitChange, standing in front of BitChange’s global headquarters in the band room, where he was meeting his executive team before gym class.