Won and Asian FX: KRW, TWD, INR and ASEAN Currencies — 2026-09-12

Top developments

Korean Won Strengthens Amid Oil Volatility

On September 11, the Korean won closed at 1,345.9 per dollar, up 6.7 won from the previous session's weekly close, defying broader emerging market weakness caused by surging crude prices. The NDF market saw the 1-month KRW/USD contract rise by 4.2 won earlier in the week due to spiking US yields and oil costs, but domestic exporter conversion and low-level buying helped stabilize the daily close. This resilience matters for regional FX as it signals that KRW's safe-haven status within Asia remains intact even as energy shocks impact other ASEAN currencies like the baht and rupiah.

Rupee Hits Session Lows, RBI Likely Intervenes

The Indian rupee fell to a session low of 95.2250 per dollar on September 10 before recovering to 95.07, leading traders to suspect Reserve Bank of India (RBI) intervention to stem the oil-driven decline. By Friday, September 11, the rupee closed at 95.57, marking its fifth consecutive day of weakness as high crude prices and foreign portfolio outflows weighed on sentiment. This volatility highlights the RBI's active role in smoothing FX markets, which contrasts with the more passive stance seen in some other Asian central banks this week.

Rupiah Weakens Against Dollar Amid Global Uncertainty

The Indonesian rupiah opened weaker on September 10, trading around Rp17,512 per dollar, as markets awaited the announcement of US Treasury buyback details and monitored global risk sentiment. Bank Indonesia’s JISDOR reference rate stood at Rp17,552 on September 9, reflecting a gradual depreciation trend pressured by strong dollar demand and higher oil imports. The rupiah's performance is critical for ASEAN FX stability, with investors watching for further BI smoothing operations to prevent excessive volatility ahead of key US economic data.

Local view

Local Korean media, including Etoday and Financial News, highlighted the "aftermath" of recent National Pension Service adjustments and low-level buying that supported the won's recovery on September 8 and 11. Traders noted that while external factors like US PPI data and oil spikes pushed NDF rates up, domestic flows prevented a sharp sell-off in the spot market. In India, Money9Live and ThePrint Hindi reported that the rupee's five-day losing streak was mitigated by RBI's "relief" through suspected market intervention, keeping the currency from breaching deeper levels. Indonesian outlets like Media Indonesia emphasized the market's cautious approach ("sikap menanti") ahead of Friday's consolidation, noting the rupiah's sensitivity to global bond yields.

Context & numbers

• KRW/USD: Closed at 1,345.9 on Sept 11 (+6.7 won); NDF 1-month traded at 1,344.80 mid on Sept 5.
• INR/USD: Closed at 95.57 on Sept 11; session low hit 95.2250 on Sept 10 before RBI-supported recovery to 95.07.
• IDR/USD: JISDOR reference rate at Rp17,552 on Sept 9; spot opened at Rp17,512 on Sept 10.
• Reserves: South Korea's international reserves stood at $428.1 billion as of end-2025, providing significant capacity for BOK smoothing operations.

On the radar

• US CPI Data: Markets are in "wait-and-see" mode ahead of the upcoming US Consumer Price Index release, which will influence Fed rate hike expectations and dollar strength.
• BOJ and Fed Decisions: The next week brings crucial interest rate decisions from the Bank of Japan and the Federal Reserve, likely triggering volatility in KRW, JPY, and broader Asian FX pairs.
• Oil Prices: Continued high crude prices remain a primary driver for INR and IDR weakness, with Brent crude surpassing $100/barrel impacting import-heavy Asian economies.