What is the value of a currency that cannot be traded or spent? Beijing has placed its most extreme ban yet on crypto transactions. It is a far cry from the days when China generated the world’s largest crypto trading volumes — and the biggest supply of bitcoins.

Cryptocurrency exchanges and other services providers were already technically banned. A loophole allowed locals to trade via offshore accounts. Chinese cryptocurrency exchanges went overseas to carry on trading — Huobi, for example, moved to the Seychelles.

China has now banned crypto transactions regardless of where exchanges and accounts are based. Regulators are set to enforce the prohibition, which includes crypto mining, with the full support of the Supreme Court, police and central bank. Binance and Huobi, the world’s largest exchanges, have halted registrations of mainland China users. Huobi will close down existing mainland user accounts this year.