The Double Terms-of-Trade Squeeze: Hormuz Oil Premium Meets El Niño Export Shock in the Rupiah's Peak Window

Rupiah Stability Watch · 2026-07-23

The premise

Indonesia's rupiah has held in the 17,900–18,100 band through successive escalations: the Strait of Hormuz toll regime, war-risk insurance premia, the El Niño food-import channel, and the governance risk premium from the Makarim/BGN reforms. In each case the capital account — SRBI carry flows, Government Regulation 24/2026 export proceeds, portfolio bond inflows — absorbed the current-account pressure. What has not been tested is a simultaneous terms-of-trade squeeze on both sides of the trade balance.

This week, two structural shifts align. The El Niño peak window (July–August) opens just as Brent has held above $85 through the weekend's US strikes on Iranian-backed militias in Jordan. The rupiah's structural repricing thesis — that capital-account strength offsets current-account weakness — now faces its stress test: higher import costs and lower export earnings at the same time.

What the evidence supports

1. Oil import bill: the Hormuz premium quantified

Indonesia imports roughly 650,000–700,000 bpd of crude and products (net of ~600,000 bpd domestic oil-equivalent production against ~1.3 mbpd consumption). At a baseline Brent of $72/bbl (the 2023–24 average before the Hormuz escalation), the annual oil import bill runs approximately $17.1–18.4 billion. At the current $85–88/bbl range — reflecting the Hormuz toll regime, war-risk insurance, and sustained escalation — the bill rises to $20.2–22.8 billion.

The incremental cost is $3.1–4.4 billion per year, or 0.25–0.35% of GDP. This is not a one-off spike; the Hormuz toll regime and war-risk premia are structural for as long as the escalation persists.

The May 2026 trade deficit of $1.61 billion — Indonesia's first in six years — was explicitly attributed by BPS to the oil and gas deficit. The oil and gas trade balance swung to a $3.2 billion deficit in May, the widest in the series. June data shows a $4.1 billion total surplus, but the oil and gas deficit persisted at $2.8 billion. The non-oil surplus is narrowing.

2. Commodity export revenue: the El Niño channel

Palm oil. The July 2025 CPO reference price of $877.89/MT (up 2.5% from June) masks a volume story. July production hit a record 5.11 million tons, but El Niño's yield impact operates on a 6–12 month lag. The 2023–24 El Niño cut 2024 production growth to 0.2 Mt vs. a decade average of 2.5 Mt. The current episode — ONI values in the +1.0 to +1.5°C range through mid-2025 — implies a similar drag on 2025–26 yields. Haze is already active: over 1,200 hotspots in Sumatra in late July, with West Sumatra and Riau declaring emergencies. SIIA's Haze Outlook 2025 rates the risk "Amber" (medium) for severe transboundary haze in H2 2025. Port and airport visibility disruptions in Dumai, Pekanbaru, and Pontianak have begun to appear in logistics reports.

Coal. H1 2025 production of 357.6 Mt and exports of 238 Mt (67% of output) look solid on the surface, but production fell 33 Mt year-on-year in January–June. The annual target of 739.7 Mt will be missed. El Niño dry-season rainfall deficits in Kalimantan (the primary coal basin) increase spontaneous combustion risk in stockpiles and reduce barge loading days on the Mahakam and Barito rivers. The 90-mine suspension in September 2025 for environmental non-compliance — concentrated in Jambi, South Kalimantan, and East Kalimantan — compounds the supply-side constraint.

Indonesia's palm oil exports reached $14.02 billion by July 2025 (+33% yoy), but the volume growth rate is decelerating. Coal export value has declined despite volume resilience, as Newcastle benchmarks softened from $140 to $115/MT. The combined commodity export revenue envelope is flattening just as the oil import bill steps up.

3. Trade deficit arithmetic: the compound effect

A single shock — oil or El Niño — would widen the current account deficit by roughly 0.3% of GDP. The simultaneous shock doubles the hit. The May 2026 deficit is the leading edge; July–August data will show whether the non-oil surplus can hold while the oil deficit deepens and commodity exports decelerate.

4. Structural repricing stress test: can the capital account hold?

The rupiah's resilience thesis rests on three capital-account pillars:

1. SRBI carry flows. Foreign holdings reached $13.3 billion by mid-2025. The BI 7-day repo rate at 5.25% (cut 25 bps in July) still offers a 250–300 bp spread over US Treasuries. But carry is rate-sensitive: if the Fed holds or BI cuts further, the spread compresses. The July cut was "dovish hawkish" — BI signaled data dependence, not an easing cycle.

2. GR 24/2026 export proceeds (DHE). Effective June 1, 2026, the regulation mandates centralized export licensing for coal, palm oil, and ferro-alloys through PT Danantara Sumberdaya Indonesia, with DHE placement in state-owned banks and 30% mandatory rupiah conversion. Realization data for June–July 2026 is not yet public. The mechanism should deliver measurable FX retention, but implementation friction (exporter onboarding, SOE capacity, conversion timing) means the Q3 2026 flow is the first real test. Early anecdotal reports suggest 60–70% compliance in the first month.

3. Portfolio bond inflows. Q2 2026 saw $7.98 billion in foreign capital inflows (BI data), reversing Q1 outflows. Government bond yields (10Y ~6.6%) remain attractive. But foreign holders have been net sellers in 7 of the last 10 weekly reporting periods through late July. The flow is fragile.

The stress test: a $7.5 bn annualized current-account deterioration requires ~$1.9 bn per quarter in net capital inflows just to stabilize reserves. Q2 2026 delivered $7.98 bn — sufficient for now. But if the Fed pauses rate cuts, if BI cuts again, or if GR 24/2026 realization undershoots, the margin narrows quickly.

What the evidence does not support

• A rupiah crash. The 17,900–18,100 range has held through worse headline risk. BI's intervention capacity (reserves ~$145 bn, swap lines, SRBI sterilization) is credible. The thesis is not collapse; it is widening deficit testing the capital-account offset.

• Immediate food-crisis transmission. The MBG procurement channel and food inflation are real (covered in prior work) but operate on a different timeline — Q4 2025 onward. The July–August window is a trade story, not a fiscal story.

• Governance risk premium as the driver. The Makarim/BGN reforms matter for medium-term investment, but they do not move the July–August current account.

• El Niño as a 2024 story only. The ONI trajectory (+1.0 to +1.5°C through mid-2025) and BMKG's dry-season forecast for Sumatra/Kalimantan confirm the peak impact window is now, not past.

The least-harm path

The policy combination that minimizes damage without creating new distortions:

1. BI: hold the 5.25% rate through August. The July cut bought credibility; a second cut before the terms-of-trade data clarifies would signal panic. The carry spread is the capital account's anchor.

2. GR 24/2026: publish monthly DHE realization data. Transparency on FX retention converts the regulation from a promise into a market observable. If June–July realization exceeds $2 bn, the capital-account math improves materially.

3. Trade ministry: expedite haze logistics corridors. Dedicated berth priority for CPO and coal at Dumai, Belawan, and Samarinda during visibility disruptions. This is a micro-intervention with macro revenue impact.

4. Finance ministry: maintain the energy subsidy envelope. The oil import bill increase ($4 bn) is fiscal as well as external. Absorbing it in the budget — not passing it to Pertamina's balance sheet — keeps the SOE's investment grade and avoids quasi-fiscal distortion.

What I'm uncertain about

1. GR 24/2026 DHE realization rate. No public data yet. The $7.5 bn annualized gap assumes 70% compliance; 50% compliance leaves a $1.5 bn quarterly hole.

2. El Niño yield lag magnitude. The 6–12 month distribution is wide. If the 2025–26 yield hit is at the 6-month tail (late 2025), the export revenue shock arrives before GR 24/2026 FX retention peaks. If at 12 months (mid-2026), the shocks stagger.

3. Fed/BI rate differential path. A September Fed cut without a BI cut widens the spread (good for carry). A BI cut without a Fed cut narrows it (bad). The September BI meeting is the next decision node.

4. Hormuz escalation ceiling. Brent at $85–88 assumes no strait closure. A blockade scenario ($110+) breaks the arithmetic entirely. The "toll regime" baseline is the working case, not the tail.

Observable signposts for July–August

The double squeeze is not a forecast of crisis. It is a measurable widening of the current-account deficit at the precise moment the capital account faces its own transition (BI easing cycle, GR 24/2026 ramp-up). The rupiah has earned its structural repricing. The next eight weeks test whether the repricing was priced for sequential shocks — or for simultaneous ones.