China's central bank on Friday said all financial transactions involving cryptocurrencies are illegal, sounding the death knell for the digital trade in China after a crackdown on the volatile currencies.The global values of cryptocurrencies including Bitcoin have massively fluctuated over the past year partly due to Chinese regulations, which have sought to prevent speculation and money laundering."Virtual currency-related business activities are illegal financial activities," the People's Bank of China (PBOC) said in an online statement Friday, adding that offenders would be "investigated for criminal liability in accordance with the law."The notice bans all related financial activities involving cryptocurrencies, such as...