When David Rubenstein, co-founder of Carlyle Group, polled his audience about their worries at a private equity conference in Hong Kong last week, many global investors identified the weak dollar as a growing concern, making them less inclined to invest in US assets today for fear that they will be worth less tomorrow.

Such fears have existed for some time but have recently gained strength. Mr Rubenstein himself characterised the ailing greenback as “a serious problem”.