Popularity becomes a drag on the ringgit, rupiah

Kuala Lumpur

THE popularity of Malaysia's ringgit and Indonesia's rupiah among global investors has made them South-east Asia's most volatile currencies, just as the region heads for troubled waters.

Already reeling from a commodity slump, debt in the two nations is seen by strategists as the most vulnerable to concerns surrounding the US presidential election and the Federal Reserve's next interest-rate increase.

One-month implied volatility in the ringgit, a measure of expected moves in the exchange rate used to price options, is the hi…