After Two Days of Gains, Here's Why the JCI Fell 1%

The Jakarta Composite Index (JCI) came under renewed pressure on Wednesday (19/8/2026), falling more than 1%. The correction was mainly triggered by selling in PT Bayan Resources Tbk (BYAN) after the stock had soared nearly 20% over the previous two trading days.

According to Indonesia Stock Exchange (IDX) trading data, the JCI weakened 1.02% or 65.61 points to 6,384.22 at 09.03 WIB. The JCI had previously closed at 6,449.83. Around ten minutes later, the JCI pared its correction to -0.57%.

Pressure on the index came mainly from BYAN shares, which slumped 14.04% to Rp14,850. The coal miner’s shares were the biggest drag on the JCI, contributing around 50.88 points of negative movement.

The correction in BYAN came after the stock had surged 20% over the previous two trading days amid widespread rumours regarding a planned acquisition of controlling shares by businessman Andi Syamsuddin Arsyad, also known as Haji Isam.

BYAN management today clarified that the company was not aware of any plan to take over or acquire approximately 62.2% of BYAN shares by Haji Isam or any party affiliated with him.

Besides BYAN, pressure on the JCI also came from a number of large-capitalisation stocks, including Bumi Resources Minerals (BRMS), which contributed -1.8 points, Amman Mineral Internasional (AMMN) -1.53 points, and Dian Swastatika Sentosa (DSSA) -0.52 points.

From a sectoral perspective, the energy sector was the main drag on the JCI with a decline of 5.71%. This sector’s correction was far deeper than that of other sectors.

Amid the pressure, several stocks were still able to support the index to a limited extent. Mora Telematika (MORA) contributed 1.12 points, Bank Mandiri (BMRI) 0.99 points, Indokripto Semesta (COIN) 0.62 points, and Charoen Pokphand Indonesia (CPIN) 0.47 points.

The JCI is expected to move in a volatile manner on Wednesday (19/8/2026). Investors tend to adopt a wait-and-see stance ahead of Bank Indonesia’s (BI) interest rate decision while also monitoring geopolitical developments and the policies of the United States central bank.

Domestically, the main focus is on the outcome of BI’s Board of Governors Meeting (RDG) held on Tuesday-Wednesday (18-19 August 2026). BI is scheduled to announce its monetary policy decision today.

The results of a CNBC Indonesia poll of 14 institutions and agencies showed that all respondents expect BI to maintain its benchmark interest rate, the BI Rate, at 5.75%.

If realised, BI will have held interest rates steady for two consecutive meetings after previously keeping the BI Rate at 5.75% in July 2026.

Investors will also be watching BI’s views on domestic economic conditions, banking liquidity, and credit growth prospects through the end of the year.

The movement of the rupiah is one of the main factors leading market participants to expect BI will not yet raise interest rates again. The rupiah has moved away from the psychological level of Rp18,000 per US dollar and is trading around Rp17,800/US$ ahead of the August RDG.

Domestically, investors are also monitoring Indonesia’s external debt data. Bank Indonesia recorded that the external debt position in the second quarter of 2026 reached US$453.4 billion, or approximately Rp8,095.5 trillion, growing 4.4% year-on-year.

Of that amount, around US$105.9 billion, or Rp1,891.7 trillion, will mature within a maximum of one year.

Nevertheless, BI considers Indonesia’s external debt structure to remain healthy. The external debt-to-GDP ratio stands at 30.6%, while around 82.1% of total external debt is long-term debt.

Meanwhile, external sentiment remains overshadowed by tensions in the Middle East. A statement by US President Donald Trump saying the Strait of Hormuz is open for shipping contradicts Iran’s assertion that the strategic waterway remains closed.

Uncertainty regarding US-Iran negotiations has again pushed oil prices higher. West Texas Intermediate (WTI) crude oil futures rose 0.4% on Tuesday to US$85.26 per barrel, while Brent strengthened 0.17% to US$91.02 per barrel.

Brent prices have strengthened 4.53% over the last three trading days, while WTI has risen 3.5% over the last four days.

Shipping disruptions in the Strait of Hormuz are also still occurring. The United Kingdom Maritime Trade Operations (UKMTO) reported that a vessel was struck by an unknown projectile while exiting the Strait of Hormuz. The incident damaged the engine room and caused one crew member to become a casualty.