In late July, after a month that saw China’s stock market crash twice and European leaders strike a last-minute deal to keep Greece in the eurozone, emerging market currencies slumped to their lowest levels in more than a decade. The weakening of the Malaysian ringgit, the Indonesian rupiah and the Brazilian real came as little surprise – all three countries are dogged by internal problems. But it symbolises a wider trend that has put investors on edge, something many fear will intensify over