Some foreign investors in China are most worried by the country’s souring relations with the West. Others fret about the unprecedented slump in its property market. Many are simply tired of losing money. Rumours that officials are considering steps to stabilise the country’s markets may have brought respite in recent days, but over the past year the CSI 300 index of Chinese shares has fallen by 22% and Hong Kong’s Hang Seng index by 30%.