Bitcoin, the world’s top virtual currency, was trading above $10,600 at 10:00 GMT, retreating from a peak of $11,090 reached earlier in the day. The surge followed a sharp plunge in the entire market on Monday after US-based exchange Coinbase informed nearly 13,000 of its users that it had to hand over their data to the US Internal Revenue Service.

Chinese financial authorities are set to bar local investors from trading virtual assets on exchanges abroad, according to unnamed sources familiar with the issue as quoted by Bloomberg. The regulators are reportedly planning to look over the bank and online-payment accounts of Chinese firms and individuals suspected of facilitating offshore cryptocurrency exchanges.

The step is reportedly aimed at blocking the remaining ways for Chinese citizens to buy virtual currencies. The country, once the world’s most active for cryptocurrency trading, prohibited trading of bitcoin and other digital currencies on domestic exchanges last year. Since then, the regulators have progressed to blocking access to platforms that provide exchange-like services.

Last year, South Korea announced tougher steps towards cryptocurrency trading in the country. The measures, designed to curb speculation and illicit activities, included taxing cryptocurrency exchanges and banning them from issuing new trading accounts.