Like other bitcoin evangelists, Ken Shishido is ready to write off the money he lost in the bankruptcy of Tokyo-based virtual currency exchange Mt. Gox as the price of revolutionizing global finance.

"In the early days of the automobile, there were traffic accidents because you didn't have traffic lights or pedestrian crossings," he said Friday, hours after Mt. Gox said it had lost up to half a billion dollars of investor funds, including some of his. "But we didn't ban automobiles."

Shishido, who lives in Tokyo, was one of about 10,000 investors in Japan who became creditors in Mt. Gox's bankruptcy when the company capped a tumultuous period of weeks by filing for bankruptcy on Friday.