Malaysia’s ringgit fell, headed for its biggest quarterly loss since 1997, as the relatively low level of import cover afforded by the nation’s foreign-exchange reserves makes the currency more vulnerable to an emerging markets selloff.

The country’s reserves have declined the most among Southeast Asia’s five biggest economies in 2015 and Moody’s Investors Service said in August that while they are sufficient, their adequacy is the weakest in the region.

The holdings recovered for a second straight fortnight in the first two weeks of September, suggesting the central bank scaled back its intervention. The currency slumped to a new 17-year low on Tuesday.

The ringgit’s drop was due to “the usual concerns around emerging-market growth and the weakness in equity markets,” said Khoon Goh, a Singapore-based foreign-exchange strategist at Australia & New Zealand Banking Group Ltd.

“Although there is already a lot of negative news priced into the ringgit, the fact that Malaysia has the lowest reserve adequacy in the region means the currency is more vulnerable during times of market volatility.”

The currency fell for a sixth day and was down 0.9 percent at 4.4650 a dollar as of 10:01 a.m. in Kuala Lumpur, according to prices from local banks compiled by Bloomberg.

It earlier dropped to 4.4690, the weakest level since January 1998, and has plunged almost 16 percent since June 30.