Bitcoin fell as much as 20% on Wednesday, piercing below $10 000, while other crypto currencies took similar spills due to investor fears that regulators could clamp down on them in an effort to curb speculation.

The world’s biggest and best-known crypto currency at one point lost 30% of its value since Tuesday. Bitcoin, despite some stabilization in late US trading, was half its record peak of almost $20 000 set on the Luxembourg-based Bitstamp exchange a month ago.

Ethereum and Ripple, the No. 2 and No. 3 virtual currencies, tumbled after reports South Korea and China could ban crypto currency trading, sparking worries of a wider regulatory crackdown.

“There is a lot of panic in the market. People are selling to try and get the hell out of there,” said Charles Hayter, founder of Crypto compare, which owns crypto currencies.

“You have more regulatory uncertainty … and because of these falls, you have these other fallouts,” he said, referring to the collapse of some crypto currencies in the recent slump in prices.

Analysts at Citi said on Wednesday bitcoin could halve again in value amid the current rout, adding that a possible fall to a range between $5 605 and $5 673 “looks very likely to be very speedy”.

With South Korea, Japan and China all making noises about a regulatory swoop, and officials in France and the United States vowing to investigate crypto currencies, there are concerns that global coordination on how to regulate them will accelerate.

Officials are expected to debate the rise of bitcoin at the upcoming G20 summit in Argentina in March.

“Crypto currencies could be capped in the current quarter ahead of the G20 meeting in March, where policymakers could discuss tighter regulations,” said Shuhei Fujise, chief analyst at Alt Design.

The current rout in bitcoin and other digital currencies was a far cry from their dramatic run-up in 2017 when main stream investors jumped on the bandwagon and as an explosion inso-called initial coin offerings (ICOs) – digital, token-based fundraising rounds – drove demand.

“Bitcoin is deciding whether this is the moment to crash and burn,” said Steven Englander, head of strategy at New York-based Rafiki Capital.

Bitcoin has plummeted before.

There have been nine instances including the current selloffgoing back to 2011 where bitcoin’s price was halved on theBitstamp exchange. The last time was from November 2014 to January 2015.