The OKX cryptocurrency exchange, one of the world’s largest, pleaded guilty on Monday to processing more than US$1 trillion (HK$7.8 trillion) in transactions by US customers without a license and will pay more than US$504 million in penalties.

The exchange, which allows users to make spot trades in more than 300 cryptocurrencies including Bitcoin and Ethereum, admitted in Manhattan federal court to a single felony count of operating an unlicensed money transmitting business.

US District Judge Katherine Polk Failla assessed the penalty in fines and forfeitures, following an agreement between US prosecutors and the exchange owner, the Seychelles-based Aux Cayes Fintech.

“Today’s settlement contained absolutely no charges of money laundering,” said David Meister, outside counsel for OKX. “Aux Cayes FinTech, one of many OKX affiliates, resolved a Department of Justice investigation by acknowledging that it had not obtained a license to operate as a money transmitter.”