An apparent mass sell-off has seen the value of almost every major cryptocurrency plummet.

A sea of red appeared on cryptocurrency exchanges on Wednesday, with 24-hour losses on many altcoins exceeding 20 per cent.

By mid-morning the losses had steadied. At 2:20pm AEST on Wednesday bitcoin was down 17 per cent, hovering at $US10,600 ($13,300), according to cryptocompare.com.

That was the lowest bitcoin had been since November, and was down almost 50 per cent from its mid-December high.

Other major cryptocurrencies also saw big losses. Ethereum was down 22.3 per cent on Wednesday afternoon, while monero was down 25 per cent.

Ripple – which has seen a huge surge in value in recent weeks  – was down 22.8 per cent.

Litecoin posted modest losses in comparison, losing around 5 per cent of its value.

The falls in value come after an unprecedented surge in the value in cryptocurrencies in recent weeks, compounded by intense media interest.

Cryptocurrency exchanges have been inundated with new customers looking to invest in the rapidly inflating altcoins, with a number a reporting technical problems as a result.

The surge in interest has prompted bubble warnings from some of the world’s best known financial figures, including legendary equities investor Warren Buffet, JP Morgan boss Jamie Dimon, Pimco founder Bill Gross – aka the ‘bond king’ – and others.

It has also apparently prompted the Chinese government to signal its intention to clamp down on industrial scale cryptocurrency mining, an activity that is heavily focused in China.

And last week in South Korea, where cryptocurrency trading is a national pastime, the government said it was preparing a bill that would ban cryptocurrency exchange website.

But despite the plummeting price, bubble warnings, regulatory interventions, cryptocurrency analysts were not predicting further losses. Cryptocompare.com was telling punters to buy bitcoin and ethereum, suggesting it believed each to have bottomed out.

Nothing in this article should be treated as financial advice. Cryptocurrencies are extremely volatile, and investing in them is risky.