Bitcoin slumped 10% Monday, continuing a steep slide and bucking a modest rebound in stocks and oil.

The cryptocurrency plunged below $4,000 over the weekend and fell below $3,650 late Monday. Last week, it lost nearly a third of its value in seven days, one of its worst weekly selloffs on record. The digital currency has now fallen by about 80% since peaking near $20,000 late last year.

Tony Gu, founding partner at NEO Global Capital, said the rout was down to just one thing: “panic.”

Many speculators have fled the market, as shown by falling trading volumes. And a split this month in a smaller currency called Bitcoin Cash has created tensions. The prospect of large investors selling bitcoin to cover the risks of a fall in the value of their Bitcoin Cash holdings has hurt sentiment.

Now, another worry has emerged: Cryptocurrency miners, the outfits that solve complex equations to generate new digital coins, seem to be losing interest. The amount of computing effort expended by miners, known as the hash rate, has started falling.