Mankun Law Firm pointed out in "Digital Currency Brick Trading Arbitrage, Beware of Foreign Exchange Trading Legal Risks" (authors: Rao Weitong, Hu Yiming) that if the "brick trading arbitrage" of digital currencies involves covert exchange between RMB and foreign currencies, it may constitute "disguised buying and selling of foreign exchange" in the crime of illegal business operations. The typical models include "receiving U against fiat currency" and "exchange trading", which essentially use digital currencies as intermediaries to bypass foreign exchange controls and disrupt financial order.