A Bitcoin ATM is seen at the Clark Street subway station in the Brooklyn Heights neighbourhood of Brooklyn in New York City, on June 13, 2022. AFP
Bitcoin, the most popular cryptocurrency, fell below the psychologically important threshold, dropping as much as 9% to less than $19,000, according to CoinDesk.
The last time bitcoin was at this level was November 2020, when it was on its way up to its all-time high of nearly $69,000.
Bitcoin has now lost more than 70 percent of its value since reaching that peak.
Ethereum, another widely followed cryptocurrency that's been sliding in recent weeks, took a similar tumble on Saturday.
It's the latest sign of turmoil in the cryptocurrency industry amid wider turbulence in financial markets. Investors are selling off riskier assets because central banks are raising interest rates to combat quickening inflation.
A spate of crypto meltdowns has erased tens of billions of dollars of investors' assets and sparked urgent calls to regulate the freewheeling industry.
Cryptocurrency lending platform Celsius Network said this month it was pausing all withdrawals and transfers, with no sign of when it would give its 1.7 million customers access to their funds.
Stablecoin Terra imploded last month, erasing tens of billions of dollars in a matter of hours.