Rupiah Slides Past Rp18,000 as Oil Prices Surge, Bank Indonesia Responds

On September 29, 2026, the rupiah traded at Rp18,024 per U.S. dollar, a level attributed by Bank Indonesia to rising global oil prices and persistent inflation concerns. Erwin Gunawan Hutapea explained that oil above US$108 per barrel and the stalled negotiations over the Strait of Hormuz have pressured the currency, which has depreciated 0.67% since the start of the quarter. Foreign-exchange reserves increased to $146.5 billion by the end of August.

The central bank noted that higher U.S. Treasury yields, now at 5.23%, are prompting expectations of tighter U.S. monetary policy, fueling demand for foreign currency among importers and prompting capital outflows from emerging-market assets. Bank Indonesia affirmed its commitment to active market presence, using NDF, spot, and DNDF transactions, as well as government-security purchases, to stabilize the rupiah and maintain liquidity. Ongoing coordination with corporations and market participants remains a priority.