Rupiah Opens Weaker at Rp17,948 per US Dollar as US Inflation Stokes Concerns

The rupiah weakened against the US dollar at the opening of trading on Thursday, 15 October 2026. The currency’s decline was influenced by rising US inflation, which reinforced market expectations about the Federal Reserve’s interest-rate policy.

Market data showed the rupiah down 45 points, or 0.25%, at Rp17,948 per US dollar. It had closed the previous session at Rp17,903 per US dollar.

Permata Bank Chief Economist Josua Pardede said rising inflation in the United States was one factor weighing on the rupiah. The data also affected investors’ expectations for the direction of the Fed’s monetary policy.

“US CPI inflation rose by 0.6% month on month in September 2026, up from 0.4% month on month in the previous month, but still in line with market expectations,” Josua said in Jakarta on Thursday, 15 October 2026.

US inflation rises to its highest since May 2026

US inflation data showed an increase in September 2026. On a monthly basis, inflation as measured by the Consumer Price Index (CPI) was 0.6%, higher than the 0.4% recorded in August 2026.

Year on year, headline inflation rose to 3.7%, from 3.4% the previous month. This exceeded the market consensus forecast of 3.6%.

US annual inflation in September 2026 was also at its highest level since May 2026. Josua said the rise in headline inflation was driven mainly by higher energy costs.

Markets are watching the figures because inflation is an important consideration for the Fed when setting interest rates.

If inflationary pressure persists or increases, the US central bank could keep monetary policy tight for longer. Such expectations could affect the US dollar and other currencies, including the rupiah.

US core inflation also increases

US core inflation also rose in September 2026. It stood at 2.6% year on year, up from 2.4% the previous month.