Bitcoin below half its peak value

The value of cryptocurrencies like Bitcoin has crashed in the last two days, with many losing half the value they had just a fortnight ago.

One expert claimed it's just part of the cycle for the volatile currencies but, clearly, investors are getting nervous.

America's Winklevoss brothers became the first Bitcoin billionaires, after investing the money they won in a lawsuit against Mark Zuckerberg, who they say stole their Facebook idea.

Now, CNBC reports more than 30-billion dollars has been wiped off Bitcoin's value.

Mark Pascall from Blockchain Labs NZ described it as a significant correction, but said it's happened before to the assets, which include other well-known currencies like Ethereum and Ripple.

"Had you bought Bitcoin a few weeks ago at its peak of US$19,000, and sold it a few days ago at $10,000 you'd have lost half," Mr Pascall said.

"But if you'd bought a year ago you'd still be up 1000 percent."

A combination of factors is making investors nervous.

"Around South Korea potentially banning it; the Chinese government and other governments regulating it," he said.

CNN reported North Korea is linked to attacks on the currencies, saying Malware used in the attacks is similar to that designed by North Korean hackers.

Last year, Acting Reserve Bank Governor Grant Spencer described Bitcoin's gains as a "bit of a bubble" and said the cryptocurrency was too unstable to be useful in the future.

In contrast, Sweden is looking at launching a national cryptocurrency, called the e-Krona, within two years.

"There are two schools of thought," Mr Pascall said.

"One, it's a giant Ponzi scheme fuelled by pure speculation; on the other side, it's the foundation for a new economy."

He said the correction isn't the beginning of the end for cryptocurrencies.

"Many times people have predicted the demise of Bitcoin over the last eight years and it continues to flourish," he said.

Mr Pascall did however warn punters to be careful and not to invest more than they can afford to lose.