Most official invitations are easily interpreted. A request to attend an embassy party is flattering. A summons to help the authorities with their inquiries is threatening. China’s invitation to attack its currency is more ambiguous. How should investors react?

The message, written in the code of regulation, requires translation. The People’s Bank of China this week said it would drop a 20 per cent reserve requirement for banks selling products such as onshore currency options. The capital charge was introduced during market chaos in late 2015. Banks passed the cost on to investors hedging or betting against the value of the renminbi. Analysts at Citi estimate it added as much as 3.5 percentage points to the price of borrowing dollars onshore for a year.

The central bank has also removed a requirement for banks to hold reserves onshore against offshore renminbi deposits. That measure was originally designed to reduce money outside China’s direct control that might be used for short selling.