The Danish national bank has released a briefing note firmly declaring bitcoin to not be money, noting that the currency is more like “glass beads”.

“Bitcoins are not money in a proper sense as there is no issuer behind them,” the report states. “Instead, bitcoins display the characteristics of a commodity to which users attach value. Unlike precious metals such as gold and silver, bitcoins have no actual utility value, bearing closer resemblance to glass beads.”

Denmark’s national bank is just the latest central bank to inveigh against bitcoin. In January, Malaysia’s central bank warned citizens that “the Bitcoin is not recognised as legal tender in Malaysia… the public is therefore advised to be cautious of the risks.” In December 2013, the People’s Bank of China banned the country’s financial institutions from trading in the currency, shortly after the former president of the Dutch Central Bank said the currency’s boom was “worse than the tulip mania”.

But the phrasing of Denmark’s intervention has raised eyebrows itself. In ascribing “actual utility value” to precious metals such as gold and silver, the bank seems to fly in the face of conventional economic reasoning. While gold and silver do have uses, in areas such as electronics and jewellery, the vast majority of their value is, just like bitcoin, maintained through little more than collective agreement.

“Bitcoin is a virtual currency without any value anchor and hence it may rise sharply or fall very suddenly. A core property of money is that its value is stable so that its purchasing power does not change markedly from day to day,” argued Hugo Frey Jensen, the governor of the central bank.

“In spite of the considerable focus, use of bitcoins as a means of payment remains very limited,” Jensen continued. “Against that background, the risks linked to their use are currently assessed to be limited to the individual user.”

The Danish bank’s warning also comes three months after a European Banking Authority warning on cryptocurrencies which stated that “you need to be aware of the risks associated with virtual currencies.” The warning fell short of regulating bitcoin, but suggested that authority is looking into the possibility.