Binance users traded US$90-billion of cryptocurrency-related assets in a single month in China, where cryptocurrency trading has been illegal since 2021, the Wall Street Journal reported on Tuesday citing internal figures and current and former employees of the exchange.

The transactions made China Binance’s biggest market by far, accounting for 20% of volume worldwide, excluding trades made by a subset of very large traders, the Journal said. The newspaper did not specify the month during which the transactions were made.

Binance’s origins lie in China, though the world’s largest crypto exchange withdrew from mainland China in 2017 during a regulatory crackdown. It did not immediately respond to a request for a comment on the Journal report.

“The Binance.com website is blocked in China and is not accessible to China-based users,” a company spokesman told the WSJ.

The exchange has also been under the scrutiny of US regulators like the Commodity Futures Trading Commission (CFTC) and the Securities and Exchange Commission (SEC).

The CFTC sued Binance for operating what it said were an “illegal” exchange and a “sham” compliance programme, while the SEC sued Binance and CEO Changpeng Zhao saying that Binance artificially inflated its trading volumes, diverted customer funds, failed to restrict US customers from its platform and misled investors about its market surveillance controls.