Bitcoin fell 11,33% to $ 33,250 at 16:00 GMT on Sunday, losing $ 4,248.98 from its previous close.
Bitcoin, the world's largest and best-known cryptocurrency, has fallen 48% from its yearly high of $64,895.22 on April 14.
Ether, the coin linked to the ethereum blockchain network, fell 16,59% to $1,915.34 on Sunday, losing $ 380.97 from its previous close.
Bitcoin markets operate 24 hours a day, 7 days a week, creating conditions for prices to fluctuate at unpredictable hours.
"Many point to bitcoin volatility as untenable," wrote RBC Capital Market's Amy Wu Silverman in a research note published Saturday. "In fact, bitcoin is making some serious and heady swings."
Bitcoin has come under pressure after a series of tweets last week from billionaire Tesla CEO and cryptocurrency backer Ilon Musk.
In addition, China on Friday cracked down on mining and trading of the largest cryptocurrency as part of ongoing efforts to prevent speculative and financial risks.
China's Financial Stability and Development Committee, chaired by Vice Premier Liu He, pointed to bitcoin as an asset it should regulate more.
The statement, which came days after three Chinese industry bodies tightened a ban on banks and payment companies providing crypto-related services, was a sharp escalation of the country's drive to stamp out speculation and fraud in virtual currencies.
China's latest campaign against cryptocurrency came after the U.S. Treasury on Thursday called for new rules that would require large cryptocurrency transfers to be reported to the Internal Revenue Service, and the Federal Reserve noted the risks cryptocurrencies pose to financial stability.