Hong Kong bitcoin exchange Bitfinex said Tuesday that hackers had stolen 119,756 bitcoin, worth approximately $72 million dollars.

News of the heist caused bitcoin to tumble by 23 percent, with its current value hovering around $556. According to Bitfinex, no other digital currency except bitcoin was targeted in the hack.

The security breach caused Bifinex to halt all trading, as well as halt all digital token deposits to and withdrawals from Bitfinex.

Bitfinex is used to trade other digital currencies too, including ether and litecoin, but the site says only bitcoins were affected.

Bifinex said they are investigating the breach to determine what happened, but acknowledged that some of their users have had their bitcoins stolen.

“We are investigating the breach to determine what happened, but we know that some of our users have had their bitcoins stolen,” said Bifinex.

“We are undertaking a review to determine which users have been affected by the breach. While we conduct this initial investigation and secure our environment, will be taken down and the maintenance page will be left up.”

This is not the first instance where an exchange has been hacked. In April, Shapeshift was hacked in what it said later was an inside job. A month later, Gatecoin was reportedly hacked to the tune of about $2 million.

These pale in comparison to Tokyo-based Mt. Gox , which shut down after losing bitcoins valued then at $474 million two years ago.