It operates out of a nondescript office tower in Finance Street and, shortened to its English acronym "SAFE", sounds like one of those fictitious shadowy organisations from a Sixties spoof spy show. But the Beijing-based State Administration of Foreign Exchange has a serious, real-world job - to manage China's towering stack of foreign currency holdings.

Once, this would not have mattered much outside China's borders, but the country's swelling trade surpluses and large capital inflows have given Safe an investment pot to rival global fund management giants. Within the next few weeks, China's reserves are due to top $1,000bn - a record for any country, let alone a developing nation like China.