Seoul shares surge over 8 pct on AI confidence, Iran-Israel ceasefire; won sharply up

South Korean stocks soared by more than 8 percent Tuesday, sharply rebounding from the over 8 percent plunge the previous session, to reclaim the 8,000-point threshold, as risk-on sentiment prevailed amid a ceasefire between Israel and Iran and confidence over the artificial intelligence (AI) boom. The local currency sharply rose against the U.S. dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) added 612.52 points, or 8.18 percent, to close at 8,096.93, after rising as high as 8,119.09.

The KOSPI posted the highest-ever daily increase, breaching the previous high of 606.64 points recorded on May 21, when the index was rallying on an extended bull run of semiconductor shares.

Trade volume was heavy at 442.4 million shares worth 46 trillion won (US$30.4 billion), with winners outnumbering losers 771 to 133. Institutions purchased a net 2.5 trillion won, while foreigners and retail investors unloaded local shares worth 2 trillion won and 618 billion won.

With the KOSPI's bullish start, the Korea Exchange had activated a buy-side sidecar for the KOSPI shortly after opening, halting program trading for five minutes.

Program trading on the KOSDAQ was also suspended for five minutes from 9:28 a.m. after the bourse operator issued a buy-side sidecar for the secondary index.

The rebound came after the KOSPI slid more than 8 percent Monday on woes over AI profitability and a possible rate hike by the U.S. Federal Reserve after the release of hotter-than-expected U.S. jobs data for May. News that Iran and Israel were trading strikes also dampened the market sentiment.

But investors' risk appetite went up Tuesday on news that Israel and Iran halted attacks on each other after a warning from U.S. President Donald Trump and a tech rebound on Wall Street.

Overnight, the Dow Jones Industrial Average closed 0.16 percent lower, while the S&P 500 rose 0.3 percent and the tech-heavy Nasdaq composite added 0.86 percent.

Micron surged 9.87 percent, SanDisk increased 5.3 percent, AI chip giant Nvidia gained 1.73 percent, and AMD went up 5.14 percent on sentiment that business fundamentals of AI-related sectors remain strong.

"As the negative factors that had triggered the sharp market decline began to ease, investors engaged in bargain hunting, particularly in large-cap semiconductor stocks, which had recently suffered steep losses," said Lee Kyoung-min, an analyst at Daishin Securities.

But analysts said the KOSPI may see continued volatility this week with the planned initial public offering of SpaceX, the earnings release of Oracle and the release of the U.S. Consumer Price Index, which will give further clues on the Fed's rate path.

The KOSPI 200 volatility index, or VKOSPI, surged more than 19 percent to close at a record high of 91.23, according to data from the Korea Exchange.

The index was higher than when the U.S.-Iran war broke out earlier this year and also during the global financial crisis in 2008.

VKOSPI is the official Korean volatility index and serves as a "fear gauge" measuring the market's expected volatility over the next 30 days based on KOSPI 200 options. Typically, VKOSPI moves in the opposite direction of the KOSPI.

Samsung Electronics, the world's largest memory chip maker, jumped 8.97 percent to 322,000 won, while its rival SK hynix shot up 15.91 percent to 2.2 million won.

AI investment firm SK Square skyrocketed 13.51 percent to 1.27 million won, while Samsung Electro-Mechanics escalated 18.39 percent to 1.97 million won.

Leading battery maker LG Energy Solution rose 2.06 percent to 396,500 won, while its smaller rival Samsung SDI gained 2.39 percent to 515,000 won.

Samsung Life Insurance increased 4.66 percent to 393,000 won, and Samsung C&T climbed 5.02 percent to 429,000 won.

Bio giant Samsung Biologics expanded 4.26 percent to 1.3 million won, and power plant manufacturer Doosan Enerbility advanced 7.58 percent to 92,300 won.

Auto shares were mixed.

Hyundai Motor was flat at 639,000 won, while its sister Kia surged 8.52 percent to 164,300 won. Hyundai Mobis dropped 2.78 percent to 595,000 won.

Internet portal operator Naver slid 7.89 percent to 257,000 won, and home appliances maker LG Electronics plunged 7.46 percent to 248,000 won.

The Korean won was quoted at 1,512.1 won against the U.S. dollar at 3:30 p.m., sharply rising 22.9 won from the previous session.

The local currency has gained ground after financial authorities issued a strong verbal intervention the previous day.

Bond prices, which move inversely to yields, closed higher. The yield on three-year Treasurys shed 8.4 basis points to 3.856 percent, and the return on the benchmark five-year government bonds dropped 8.8 basis points to 4.102 percent.

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This story was originally published June 9, 2026 at 3:45 AM.