Bitcoin tumbled to its lowest level since February as the meltdown in the world’s largest digital currency accelerates, renewing concern about the long-term viability of the much hyped alternative to traditional currencies.

The price of the digital coin fell as low as US$6,498, bringing the slide for the year to more than 50 per cent. It’s down from a record high of US$19,511 reached in December, the culmination of the more than 1,400 per cent surge seen in 2017 as Bitcoin burst on to the mainstream.

Cryptocurrencies have been beset by a string of bad news. Most recently was the “cyber intrusion” on the South Korean cryptocurrency exchange Coinrail this past weekend that appeared to result in a loss of an unknown quantity of digital currency.

Back in May, the sector found itself under increasing government scrutiny when the Justice Department opened up a criminal probe into illegal trading practices that can manipulate the price of Bitcoin and other digital currencies. And earlier that same month, Bitcoin got no love from two of the world’s wealthiest men, Bill Gates and Warren Buffett, with the latter calling the currency "probably rat poison squared."