The KOSPI index, which had surged more than 8% the previous day, plunged in a day, sliding to 7,730 points. After a 5% drop on the 5th, an 8% plunge on the 8th, and an 8% surge on the 9th, it fell more than 4% again on the day, continuing an intense "roller-coaster market" in Korea's stocks. Compared with the 4th (8,639.41), the KOSPI index fell more than 900 points in a week.
The KOSPI closed at 7,730.82, down 366.11 points (4.52%) from the previous trading day. Opening at 7,899.77, the KOSPI widened losses during the session, giving up the 7,800, 7,700, and 7,600 levels in succession. As losses deepened to more than 6% in the afternoon, a "sell sidecar" was triggered, suspending the effectiveness of program sell quotes for five minutes.
Foreign net selling continued for 23 trading days. In the main board, foreigners were net sellers of more than 3.2 trillion won (combined Korea Exchange (KRX) and NEXTRADE (NXT)), while individuals were net buyers of 5.8 trillion won, absorbing supply. Institutions also were net sellers of 2.9 trillion won. Among institutional categories, brokerages that capture ETF flows showed 2 trillion won on the sell side, and the national pension funds were also net sellers of 260 billion won.
The market, which had rebounded to reclaim the 8,000 level the previous day, plunged again, a move attributed to overlapping impacts from Middle East–driven geopolitical risk and worries about a slowdown in artificial intelligence (AI) investment. As the U.S. Central Command said it had launched military operations against Iran, investor sentiment weakened, and news that large-scale data center developer Crusoe had halted development on some projects also dampened expectations for AI infrastructure investment.
As market volatility has increased recently, forced liquidation has also expanded quickly. According to the Korea Financial Investment Association, forced liquidation over the past month (May 11–June 8) totaled 1.0972 trillion won, about five times the January figure (216.6 billion won). On just two days, the 5th and 8th, when the KOSPI plunged, 305.3 billion won in forced liquidation was executed.
The No. 1 and No. 2 market-cap stocks on the main board fell around 7%, showing high volatility. Samsung Electronics tumbled 6.06%, barely holding 300,000 won at the close, and SK hynix fell 7.54%. Most top market-cap stocks dropped sharply, including Samsung Electro-Mechanics (-8.38%) and SK Square (-6.78%). Kakao also fell, after staging the first partial strike since its founding on the day and signaling a second strike on the 29th.
The KOSDAQ market also slid to the 950 level as profit-taking emerged right after a 6% rebound the previous day. The KOSDAQ index closed at 951.63, down 16.18 points (1.67%) from the previous trading day. While foreigners and institutions were net sellers of 51.7 billion won and 120 billion won, respectively, individuals alone were net buyers of more than 168 billion won.
Most top market-cap stocks, including Alteogen, EcoPro BM and EcoPro, fell. In contrast, corporations in semiconductor materials, parts and equipment (SME)—such as PSK (5.50%) and Jusung Engineering (3.81%)—rose, and Voronoi gained 6.17% on expectations for accelerated approval to start an anticancer clinical trial.
Meanwhile, the U.S. consumer price index (CPI) for May, to be released this evening Korea time, is also cited as a factor that could steer the market. The market expects the May CPI to rise 4.2% year over year and core CPI to rise 2.9%. If inflation comes in higher than expected, concerns about a Federal Reserve rate hike could grow, likely weighing on stocks.
Lee Kyung-min, an analyst at Daishin Securities, said, "Although the market is already pricing in inflation pressure from the recent rise in energy, if inflation indicators come in higher than expected, concerns about Fed rate hikes could grow and investor sentiment could weaken."