The year so far has not been kind to emerging market currencies. Led by Brazil, where the real lost 25 per cent against the US dollar, Asian ones are also suffering this summer, shedding between 3 and 9 per cent of face value. The one currently looking most at risk of a rout is the Indonesian rupiah having weakened over five consecutive quarters. Unlike the Asian crisis in 1997-1998, moves are steady so observed volatility is low, but do not be fooled because the break above 12,500 is important. Though overbought on the Relative Strength Index the risk is that bullish momentum will send it over the edge, tumbling to 15,500 and then the old record low at 16,800.