Jakarta. Indonesia’s benchmark stock index opened in the red on Wednesday as escalating geopolitical tensions in the Middle East rattled global markets and drove investors into risk-off mode.

Jakarta Composite Index (JCI) fell 43 points, or 0.54%, to 7,896 in early trading, moving within a range of 7,818–7,897.

Market activity remained brisk in the first minutes of trading. Data from RTI showed volume reaching 4.44 billion shares with turnover of Rp 1.83 trillion ($108.08 million) across more than 209,000 transactions. Declining stocks dominated the market, with 406 falling against 148 gainers, while 135 were unchanged.

Phintraco Sekuritas said concerns that the conflict involving the United States, Israel, and Iran could last longer than previously expected had weighed on market sentiment.

“Concerns that the US and Israel’s war against Iran could last longer than initially anticipated have become a negative sentiment driving the JCI’s weakness,” the brokerage wrote in its Wednesday research note.

Additional pressure also came from corrections in several energy and mining stocks. Phintraco noted that the Energy and Mineral Resources Ministry had set Indonesia’s 2026 nickel ore production target at 209.08 million tons, lower than the previously planned 2026 work and plan budget (RKAB) output range of 260 million to 270 million tons.

The brokerage also warned that Iran’s threat to close the Strait of Hormuz could trigger turbulence in global energy markets, with Asian economies expected to bear the brunt of the impact.

The strait serves as a key artery for global oil trade, with roughly 13 million barrels per day passing through the route in 2025, accounting for around 31% of global seaborne crude oil flows. “A prolonged closure of the strait could push crude oil prices higher, potentially fueling inflation and influencing central banks’ monetary policy decisions,” Phintraco added.

On the domestic front, Kiwoom Sekuritas Indonesia said the Indonesia Central Securities Depository (KSEI) and the Indonesia Stock Exchange (IDX) had begun submitting investor share ownership reports exceeding 1% in listed companies.

The move follows the Financial Services Authority (OJK)’s Board of Commissioners Decision No. 1/KDK.04/2026 and is part of efforts to improve transparency in Indonesia’s equity market in response to MSCI’s request regarding the free-float transparency of Indonesian stocks.

Global markets also provided a negative lead after Wall Street closed lower overnight as the Middle East conflict expanded, sparking fears of rising inflation driven by higher energy prices. Kiwoom Sekuritas said global market sentiment had shifted firmly into risk-off mode as the conflict entered its fourth day with intensifying strikes between the US, Israel, and Iran.

Iran’s attacks on energy facilities and tankers in the Gulf region, along with threats to close the Strait of Hormuz, through which about one-fifth of the world’s energy supply passes, have heightened concerns over global supply disruptions.

Investors are increasingly assessing that the conflict could last longer than initially expected, raising the risk of energy-driven inflation while weighing on global economic growth.

“The surge in oil prices is seen as an energy supply shock that could drive global inflation higher and force central banks to maintain tighter monetary policies for longer,” Kiwoom said.

Overnight in the US, the S&P 500 dropped 0.9%, while the Dow Jones Industrial Average fell 403 points, or 0.8%, after plunging more than 1,200 points earlier in the session. The Nasdaq Composite closed down 1%.

Oil prices surged after Iran struck the US Embassy in Saudi Arabia and expanded attacks to areas critical to global oil and gas production, raising fears over energy supply disruptions. Tensions escalated further after Iranian Brig. Gen. Ebrahim Jabbari, an adviser to the Islamic Revolutionary Guard Corps, warned that ships passing through the Strait of Hormuz could be set on fire.

However, concerns eased slightly later in the session after President Donald Trump said the US Navy could escort tankers through the strait if necessary to ensure the free flow of global energy supplies.

Regional markets also opened sharply lower on Wednesday. Japan’s Nikkei dropped 1.45% to 55,470, while South Korea’s Kospi slid 3.55% to 5,592. Hong Kong’s Hang Seng fell 1.17% to 25,469, and China’s Shanghai Composite declined 2.32% to 4,087.

The MSCI Asia Pacific Index dropped 3.5%, reflecting broad selling pressure across regional equities.

According to Kiwoom, South Korea was the worst-performing market on Tuesday, with the Kospi plunging between 4.3% and 7.2% amid profit-taking in major technology stocks such as Samsung Electronics and SK Hynix.

In Japan, the Nikkei 225 and TOPIX both fell more than 2% following mixed domestic economic data and hawkish remarks from the Bank of Japan regarding the possibility of further interest rate hikes.