Booms start off slowly but busts can be sudden and devastating. So the growth in China’s trust industry from Rmb1tn in assets under management in 2007 to Rmb5.3tn ($831bn) today, or a tenth of the nation’s output, should not be ignored.

True, China’s trust industry – which serves as an intermediary making loans and then repackaging them as debt products for investors – has been vital in boosting returns for China’s wealthy. Interest rates are superior to deposits and there is a lack of alternatives.

And the sector is profitable – net income among China’s 66 trust companies surged by almost a half last year. That is good for big shareholders in trust companies such as state-owned enterprises (Baosteel and Citic Group), local governments and listed insurers PICCand Ping An.