USD/IDR fell back after touching a new record high of 18,190, following Bank Indonesia’s unscheduled 25 bps rate rise to 5.50%. The move came more than a week before its next scheduled meeting and followed a surprise 50 bps increase on 20 May, with the central bank framing the decision as support for rupiah stabilisation and a pre-emptive step to keep inflation in 2026 and 2027 within the government’s target range.
On valuation metrics, the rupiah is 10% undervalued versus its real effective exchange rate trend, the deepest gap since 2009. Bank Indonesia’s tightening cycle, alongside continued FX intervention, points to constraints on further IDR depreciation, while the currency’s discount is presented as persisting until the energy shock eases. The piece was produced with an Artificial Intelligence tool and reviewed by an editor.
Central Bank Action Limits USD/IDR Upside
Given Bank Indonesia’s surprise rate hike to 5.50%, we see the sharp rise in USD/IDR as capped for now. The central bank has shown it is willing to act aggressively and ahead of schedule to defend the rupiah, putting a firm resistance level near the recent 18190 high.
This intervention suggests that implied volatility in USD/IDR options is likely to decrease from its recent peak. We believe selling volatility is the correct move, as the central bank’s actions should contain the pair within a more predictable range in the short term. The market’s one-way panic has been forcefully interrupted.
Market Strategies and Underlying Pressures
The underlying pressure from the energy shock, however, remains a key factor keeping the rupiah weak. With Brent crude prices staying above $100 per barrel this past quarter and Indonesia’s current account deficit widening by 8% in the first quarter of 2026, a significant strengthening of the IDR is unlikely. This is why the currency remains nearly 10% undervalued, a level we haven’t seen since the 2009 global financial crisis.
Therefore, for the coming weeks, we will be looking at range-trading strategies. We plan to sell out-of-the-money USD/IDR call options to collect premium, betting that the central bank’s defense will hold. This strategy benefits from both the defined ceiling on the pair and the expected decline in volatility.
The increased policy rate also improves the carry for holding rupiah, making it more attractive relative to the dollar. This higher yield differential should put downward pressure on USD/IDR forward points. We will factor this improved carry into our positioning, as it provides a tailwind for any short USD/IDR exposure.
