Seoul stocks closed sharply higher Monday, extending their winning streak to a third day as investors poured into risk assets on news that the United States and Iran had reached an agreement to end their monthslong war. The benchmark Korea Composite Stock Price Index rose 422.36 points, or 5.2%, to 8,545.98, after touching an intraday high of 8,603.48.
The rally marked the third consecutive session of gains for the KOSPI, which has swung sharply in recent weeks as traders priced in alternating headlines of conflict and diplomacy. The index surpassed the psychologically significant 8,500-point mark for the first time since the Iran war erupted in March, according to market data from the Korea Exchange.
“The KOSPI broke the 8,500-point mark as the breakthrough in peace talks opened a risk-on rally,” Lee Kyoung-min, an analyst from Daishin Securities, said in a note. He said foreign investors were net buyers, adding upward pressure to the stock market, along with institutional investors. The Korean won rose sharply against the U.S. dollar during Monday’s session.
The Korea Exchange issued a sidecar — a temporary halt in index futures trading designed to cool excessive volatility — shortly after the market opened. The regulator has triggered the measure 14 times since the war began, exchange data show.
Trump announced the agreement Sunday (local time), saying he has “reached an agreement with Iran to end their war” and that he will authorize the toll-free opening and removal of the naval blockade in the Strait of Hormuz. An official signing ceremony is scheduled to take place in Switzerland on Friday, according to the White House.
The conflict between the U.S. and Iran began in early March after Trump ordered airstrikes in response to attacks on U.S. assets. The war sent oil prices surging and rattled global markets, with South Korea’s export-driven economy particularly exposed to disruptions in Middle East shipping lanes. Monday’s rally suggests investors are betting the formal peace deal will restore stability and revive trade flows through the strategic waterway.