Bitcoin skeptics such as JPMorgan CEO Jamie Dimon have often claimed that Bitcoin is “worth nothing.” For approximately 18 minutes at one cryptocurrency exchange in Japan, these skeptics were right.

On Tuesday, Zaif — a cryptocurrency exchange operated by Osaka-based Tech Bureau Corp. — revealed in a statement that a technical error had allowed several traders to purchase Bitcoin for 0 yen, a considerable discount off its fair market value of ~1.2 million yen.

Zaif said that the glitch occurred during an 18-minute window on Feb. 16, and seven customers were able to purchase BTC at the 0 yen rate. The company has since corrected customer balances, although it said that is still trying to sort the matter out with one of the traders, who apparently attempted to transfer the coins out of the exchange following the transaction.

The glitch caused the system to temporarily report inaccurate trading data but otherwise had no effect on the platform’s other users.

“We apologize for any inconvenience and inconvenience caused to you by our customers,” the company said in the statement, according to a rough translation. “We will strive to prevent recurrence and we will continue to work on improving our services.”

According to data from CoinMarketCap, Zaif processed $17.3 million worth of trading volume over the preceding 24 hours, ranking it 51st among exchanges that charge trading fees. This, however, does not include the exchange’s BTC volume, which the website reports as depicting abnormal activity.

Reuters reports that Zaif is one of 16 cryptocurrency exchanges that are currently licensed by Japan’s Financial Services Agency (FSA). Another 16 — most notably the recently-hacked Coincheck — have been allowed to continue operating while their registration applications are pending.

The FSA conducted spot inspections of these exchanges following the Coincheck hack, which occurred at the end of January and resulted in the theft of $530 million worth of NEM tokens (XEM), making it the largest ever cryptocurrency exchange heist.

As CCN.com reported, the 16 licensed exchanges are currently drafting plans to establish a self-regulatory body that will be registered with the FSA.

Featured image from Shutterstock.