Emerging market (EM) currencies have tumbled against the US dollar over the past three months – with a single exception. Not only has the renminbi resisted kowtowing to the resurgent greenback, it has strengthened against it even as the currencies of its BRIC counterparts – the real, the rouble and the rupee – have fallen 7.8 per cent, 14.3 per cent and 1.6 per cent respectively since July.

This raises an obvious question: for how long can the renminbi refuse to accept the US dollar renaissance?

For some, the answer is straightforward. Charles Dumas, chief economist at Lombard Street Research, thinks the renminbi must be cut loose from its moorings if China is to boost exports – its only available palliative to offset the impact of a slowing economy.