Back in 2011, wealthy Chinese investors fell in love with a structured product called Credit Equals Gold No. 1. It raised $500 million to back a coal-mining venture in the north of the country, by offering a return of 10%. It was sold through the offices of a reputable bank. It was issued by China Credit, 33% owned by the state.

Three years on, the company cannot repay its debt. According to the Wall Street Journal, its owner has been detained by the authorities in connection with his financial affairs and could not be reached for comment. Investors are being bailed out, says China Credit.