"A cocktail of uncertainty is dominating the market, made up of monetary policy imponderables, a fear of liquidity shortage and the withdrawal of institutional capital," analyst Timo Emden of Emden Research said.
The world's oldest and best-known cryptocurrency has lost about 45 per cent since a November peak of more than $US126,000, amid strong demand for the traditional safe havens gold and silver.
Bitcoin fell to a low of $US66,675.12 on Thursday, its weakest since October 2024, a month before Republican Donald Trump won the US presidential election, having signalled his intention to support crypto on the campaign trail.
"As before, we are not witnessing a classic crash but a creeping decline in value and appetite for risk," Emden said.
Thousands of cryptocurrencies have emerged after bitcoin's success.
However, with a market capitalisation of about $US1.4 trillion ($A2 trillion), bitcoin remains by far the dominant digital currency, followed at a considerable distance by ethereum at about $US250 billion and Tether at roughly $US185 billion.
The CoinMarketCap website puts the total value of cryptocurrencies at about $US2.4 trillion, down from $US3 trillion at the start of the year.
with Reuters
