Hong Kong: Bitcoin fell the most in a week after the company behind cryptocurrency tether reported a $31 million (Dh114 million) theft.

The amount was taken from the Tether Treasury wallet on Nov. 19 and sent to an unauthorised bitcoin address, according to an announcement on the company’s website posted on Tuesday. The stolen tokens will not be redeemed, and the company is trying to prevent them from entering the ecosystem, it added. Bitcoin dropped as much as 5.4 per cent, the most since Nov. 13. It was last trading 1.6 per cent weaker at $8,117.

The incident is the latest in a long list of hacks that have dented confidence in the security of cryptocurrencies. Such events typically have fleeting market impact: bitcoin has surged to one record after another during the past few years despite major thefts from exchanges including Bitfinex and Mt. Gox.

Tether, with a market capitalisation of $673 million, is the world’s 19th most-valuable virtual currency, according to data on Coinmarketcap.com. The tokens are pegged to fiat currencies, allowing users to store and transfer globally and instantly, according to the website. One tether is equal to a dollar.