The Financial Markets Authority is has issued a strongly-worded warning for Kiwis considering taking a punt on cryptocurrency.

The watchdog made its comments to the Herald following Bitcoin's latest rollercoaster move - the value of the digital currency has fallen by about a third since Friday after doubling over the past month - and a similar advisory issued by its opposite number in the UK, the Financial Conduct Authority or FCA.

"New Zealanders considering purchasing cryptocurrencies, such as Bitcoin, should be aware that these are high risk and highly volatile assets," an FMA spokesman said.

"Cryptocurrencies are not regulated in New Zealand and are often exploited by scammers and hackers.

"The FMA shares the FCA's concerns that some crypto exchanges are promising high returns and customers should be prepared to lose all of their money.

"Many overseas cryptocurrency exchanges are unregulated and operate exclusively online – with no connection to New Zealand. This makes it hard to find out who is offering, exchanging, buying or selling the cryptocurrencies"

If you are planning to buy cryptocurrency, you should at the very least ensure that the exchange is registered on the Financial Service Providers Register (FSPR), which gives you access to a dispute resolution scheme, the FMA spokesman said.

"You should also check if the exchange holds your New Zealand dollars in a trust account."

While a lot of the narrative around Bitcoin has focussed on the cryptocurrency's rollercoaster valuation, people who purchase any digital currency need to be aware of practical issues too, such as how easy it is to convert to a fiat currency.

The $30m Cryptopia heist, involving a Christchurch-based cryptocurrency exchange that operated globally, has also highlighted that crypto deposits are not guaranteed - unlike most traditional currencies, where a government will usually step in either by law or political pressure in the event of a major loss.

Liquidators from Grant Thornton, and police, are still trying to untangle what happened in the Cryptopia hack, which occurred in January 2019.

3 things you need to know about cryptocurrencies like Bitcoin

• They're high risk and highly volatile – the price can go up and down very quickly
• They're not regulated in New Zealand
• Cryptocurrencies, crypto-exchanges and the people that use them are often the targets of hacking, online fraud and scams