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Kospi opens markedly lower after Trump renews threats against Iran

Published: 31 Mar. 2026, 10:05 Updated: 31 Mar. 2026, 10:59

KIM MIN-YOUNG
[email protected]

A trading room at Hana Bank in central Seoul on March 31 [YONHAP]

Korean stocks opened markedly lower on Tuesday as U.S. President Donald Trump renewed threats against Iran, with no end in sight to the monthlong war in the Middle East.

After opening 2.53 percent lower, the benchmark Kospi extended losses, falling 203.78 points, or 3.86 percent, to 5,073.52 in the first 15 minutes of trading.

On Monday, Trump threatened to “completely obliterate” Iran's Kharg Island, a key oil hub, and its power plants and oil wells if a peace deal with the United States was not reached “shortly.”

The conflict, which began in late February following the U.S.-Israeli strikes on Iran, has been escalating, as Iran-backed Houthi militants in Yemen joined the war, stoking fears of further disruptions to global oil supplies.

Tehran, however, dismissed the peace proposals as “unrealistic, illogical and excessive,” and a parliamentary security committee approved a draft bill to introduce a toll system for the Strait of Hormuz, according to foreign media reports.

Israeli Prime Minister Benjamin Netanyahu said the war had achieved more than half of its goals, though he did not put a timeline on when it would end.

Overnight, U.S. shares finished mixed. The Dow Jones Industrial Average climbed 0.11 percent, while the tech-heavy Nasdaq Composite sank 0.73 percent. The S&P 500 lost 0.39 percent.

U.S. President Donald Trump speaks at the National Republican Congressional Committee's annual President's Dinner at Union Station in Washington, D.C. on March 25, 2026. [AFP/YONHAP]

Losses were especially pronounced in semiconductor stocks as concerns spread that a prolonged war in the Middle East could disrupt supplies and chip production. Nvidia fell 1.4 percent, and ASML dropped 3.72 percent, sending the Philadelphia Semiconductor Index down 4.23 percent.

In Seoul, most big-cap shares lost ground amid heavy selling by foreign investors.

Market bellwether Samsung Electronics slid 4.76 percent, and chip giant SK hynix sank 7.22 percent.

Top automaker Hyundai Motor dropped 4.05 percent, and its sister affiliate Kia tumbled 4.75 percent.

Leading battery maker LG Energy Solution lost 3.17 percent, and AI investment firm SK Square dipped 8.14 percent.

Bio giant Samsung Biologics decreased 0.65 percent, and Celltrion went down 1.64 percent.

Defense giant Hanwha Aerospace declined 4.36 percent, and nuclear power plant builder Doosan Enerbility fell 1.65 percent.

Leading shipbuilder HD Hyundai Heavy shed 0.52 percent, while its rival Hanwha Ocean rose 2.96 percent.

A map showing the Strait of Hormuz and a 3D printed miniature model depicting U.S. President Donald Trump are seen in this illustration taken March 23, 2026. [REUTERS/YONHAP]

The won weakened by 8 won from the previous session to trade at 1,523.7 against the dollar as of 9:15 a.m.

In London trading overnight, the won-dollar rate rose as high as 1,521.1, setting a new high since the 2008 global financial crisis. As of 9:31 a.m. on Tuesday, it was at 1,527 won, up 9.5 won from the previous day.

Amid heightened geopolitical anxiety, West Texas Intermediate crude for May delivery rose 3.25 percent to settle at $102.88 a barrel, its highest level since July 2022.

BY KIM MIN-YOUNG, YONHAP [[email protected]]