Bitcoin slumped to the lowest level since December in Asia trading hours as cryptocurrencies continued a January selloff amid rising scrutiny from global regulators.

Bitcoin fell 6.3% to US$13 040 at 10.32am in Hong Kong, the lowest level since 5 December according to composite Bloomberg pricing, bringing an end to a rally over the past two days.

Bitcoin is now down more than 30% from the record high in mid-December. Rival cryptocurrencies are also down, including a drop of as much as 17% in Ripple.

Investors “should be prepared to lose all their money” in bitcoin, said Steven Maijoor, chairman of the European Securities and Markets Authority (ESMA), in a Bloomberg TV interview in Hong Kong. “It has an extremely volatile value, which undermines its use as a currency. And it’s also not broadly accepted.”

The ESMA warned retail investors against initial coin offerings in November and is monitoring developments in cryptocurrencies, Maijoor said.

China, which first began targeting the industry last year, is escalating its clampdown on cryptocurrency trading, targeting online platforms and mobile apps that offer exchange-like services, according to people familiar with the matter. — Reported by Eric Lam, (c) 2018 Bloomberg LP