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

SEOUL, June 9 (Yonhap) -- 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.

A dealing room at Hana Bank in Seoul on June 9, 2026 (Yonhap)

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 p