Bitcoin shrank 10 percent to $33,747.21 at 1400 GMT (10 a.m. ET) on Sunday, losing $3,753.33 from its previous close.
Bitcoin, the world’s biggest and best-known cryptocurrency, is down 48 percent from the year’s high of $64,895.22 on April 14.
Ether, the coin linked to the ethereum blockchain network, dipped 14 percent to $1,973.96 on Sunday, losing $322.35 from its previous close.
Bitcoin markets operate 24/7, setting the stage for price swings at unpredictable hours.
Bitcoin had been under pressure after a series of tweets last week by billionaire Tesla Chief Executive and cryptocurrency backer Elon Musk, chiefly his reversal on Tesla accepting bitcoin as payment.
In addition, on Friday China 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, singled out bitcoin as the asset it needs to regulate more.
China’s latest campaign against crypto came after the U.S. Treasury Department on Thursday called for new rules that would require large cryptocurrency transfers to be reported to the Internal Revenue Service, and the Federal Reserve flagged the risks cryptocurrencies posed to financial stability.