SHANGHAI—Chinese regulators have tightened restrictions that ban financial institutions and payment companies from providing services related to cryptocurrencies, marking a fresh crackdown on digital money. Compared with a previous ban issued in 2017, the new rules greatly expanded the scope of prohibited services, and judged that “virtual currencies are not supported by any real value.” What Are the New Measures? Three financial industry associations on Tuesday directed their members, which include banks and online payment firms, to not offer any crypto-related services, such as account openings, registration, trading, clearing, settlement, and insurance, reiterating the 2017 ban. But the new ban, which was posted by the People’s Bank of China (PBOC), also covers services that were not previously mentioned. For example, it made clear that institutions must not accept virtual currencies, or use them as a means of payment and settlement. Nor can institutions provide exchange services between cryptocurrencies and the …