From 7,200 to the 6,800 level… ‘Rollercoaster KOSPI’ closes down about 1%
KOSPI closes down 1.55% at 6,869.83
Institutional Investors Net Sold 785.2 Billion vs. Retail Investors Net Bought 731.7 Billion
High of 7,216.62 → Low of 6,788.78… Trading Range Exceeds 400 Points
KOSDAQ Falls 3.52%… Rechargeable Battery and Biotech Sectors Drop in Tandem
Shin Ha-yeon
2026-08-18 15:33:58
Share
[Edaily Reporter Shin Ha-yeon ] The KOSPI index crossed the 7,200 mark early in the session on the 18th but ended the day down more than 1% after a roller-coaster ride that saw it fall as low as the 6,700 level during the session. With institutional investors net selling nearly 800 billion won, the number of declining stocks exceeded 680, dampening overall market sentiment.
According to MP Doctor on the 18th, the KOSPI closed at 6,869.83, down 108.11 points (1.55%) from the previous trading day. The index opened at 7,127.77, up 2.15% from the previous trading day, and surged to 7,216.62 early in the session, but turned lower during the morning. It subsequently extended its losses, dropping as low as 6,788.78 during the session, and after experiencing significant volatility, closed below the 6,900 mark. A view of the scoreboard in the Hana Bank dealing room in Jung-gu, Seoul, on the afternoon of the 18th. On that day, the KOSPI closed at 6,869.83, down 108.11 points (1.55%) from the previous session. The KOSDAQ also closed at 834.20, down 30.45 points (3.52%) from the previous session. (Photo = News1) In terms of supply and demand, institutional investors recorded net sales of 785.2 billion won on the stock market, dragging down the index. Retail and foreign investors recorded net purchases of 731.7 billion won and 86.1 billion won, respectively. Program trading, combining arbitrage and non-arbitrage transactions, showed a net selling position of 1.2615 trillion won.
Semiconductor stocks, which had led the index higher early in the session, quickly gave up their gains in the afternoon, resulting in mixed performance across individual stocks. SamsungElectronics closed at 268,500 won, down 6,000 won (2.19%) from the previous trading day, while SK hynix closed at 1,662,000 won, up 17,000 won (1.03%).
During the session, SamsungElectronics rose 4.92% from the previous close to 288,000 won, and SK hynix surged 8.95% to 1,792,000 won, but both subsequently gave up most of their gains. Following the strength in U.S. memory semiconductor stocks overnight, domestic semiconductor stocks also showed strength driven by momentum in AI infrastructure investment; however, the strong upward trend centered on semiconductors seen early in the session did not hold as profit-taking selling pressure intensified toward the end of the session.
Stocks with the highest market capitalization were generally weak. SKSQUARE(402340)(-1.65%), SamsungElectroMechanics(009150)(-7.57%), HyundaiMotor(005380)(-3.97%), LG Energy Solution(373220)(-5.01%), and SAMSUNG BIOLOGICS(207940)(-1.10%) all fell. In contrast, Samsung Life Insurance(032830)(3.16%) rose, while SAMSUNG C&T CORPORATION(028260) and KB Financial Group(105560)closed flat.
By sector, the market was generally weak. IT services closed down by around 5%, and securities also fell by around 4%. Following these, machinery and equipment, transportation equipment and parts, construction, medical and precision instruments, entertainment and culture, pharmaceuticals, electricity and gas, general services, manufacturing, metals, electricity and electronics, textiles and apparel, chemicals, finance, and retail all closed lower. In contrast, insurance, transportation and warehousing, and telecommunications rose.
KOSPI trading volume totaled 399.04 million shares, with a total trading value of 29.6448 trillion won. Including five stocks that hit their upper price limit, 195 stocks rose, while 682 fell. Twenty-nine stocks traded flat, and no stocks hit their lower price limit.
Kim Ki-baek, an analyst at Shinhan Investment Securities, noted, “Early in the session, the index broke through the 7,200 level, buoyed by the previous day’s gains in semiconductor stocks, but later closed lower due to profit-taking.” He added, “It is possible that the resurgence in international oil prices and the rise in long-term interest rates—particularly in the U.S.—directly impacted valuations.” He continued, “Factors such as the KOSPI volatility index showing a downward trend and concerns over semiconductor companies’ fundamentals easing compared to June and July could act as variables favorable to the medium- to long-term direction.”
He further predicted, “Going forward, the key to volatility in the domestic stock market will be whether the holdings of single-stock leveraged exchange-traded funds (ETFs) continue to decline,” adding, “Considering the current rate of decline in these holdings, investors’ attention could shift toward fundamentals in about three to four weeks.” However, he added, “Uncertainty in the Middle East remains a factor that could cap the index’s upside for the time being.”
On the same day, the KOSDAQ Index closed at 834.20, down 30.45 points (3.52%) from the previous trading day. By investor type, institutions were the sole net sellers, offloading 416.5 billion won worth of shares, while retail investors and other institutions were net buyers, purchasing 389.3 billion won and 36.8 billion won worth of shares, respectively.
Among the top market-cap stocks, Alteogen Inc.(196170)(-5.10%), ECOPRO CO., LTD(086520)(-6.94%), ECOPRO BM CO., LTD.(247540)(-6.51%), Rainbow Robotics(277810)(-6.19%), WONIK IPS Co.,Ltd.(240810)(-3.60%), LEENO Industrial Inc(058470)(-4.24%), and ABL Bio Inc.(298380)(-5.11%) all fell sharply. In contrast, JUSUNG ENGINEERING Co.,Ltd.(036930)(0.84%) and EO Technics Co., Ltd.(039030)(2.48%) closed higher.
Meanwhile, overnight on the New York Stock Exchange, all three major indexes fell in unison due to rising international oil prices stemming from heightened tensions between the U.S. and Iran, as well as the aftermath of a sharp rise in U.S. Treasury yields. On the 17th (local time), the Dow Jones Industrial Average closed down 0.51%, the S&P 500 index fell 0.52%, and the Nasdaq Composite Index dropped 0.32%. In contrast, semiconductor stocks showed relative strength—with Micron rising about 4%—and the Philadelphia Semiconductor Index also rose 1.6%.
This week, the domestic stock market is expected to attempt a rebound driven by strength in the semiconductor sector, while continuing to experience volatile trading conditions influenced by macroeconomic factors such as interest rates and oil prices.
Han Ji-young, an analyst at KIWOOM Securities, noted, “The strength of U.S. semiconductor stocks such as Micron and SanDisk during the holiday period could drive gains in the domestic stock market early this week,” but added, “Given the coexisting macroeconomic uncertainties—such as interest rates and oil prices—there is a possibility that profit-taking and pressure to slow the pace of the rally could emerge following the short-term surge early in the week.”
She continued, “We should avoid interpreting this as the end of the rebound,” noting, “We have now entered a recovery phase where positive catalysts are beginning to take effect as normal.” He added, “As the market processes the minutes of the July Federal Open Market Committee (FOMC) meeting, U.S. economic indicators, and South Korean export data scheduled for release this week, it will be important to see whether risk appetite and the trend of foreign investors halting net selling are sustained, and whether volatility indicators continue to stabilize.”
ABLE C&C(078520)is establishing a subsidiary in the Netherlands to serve as the control tower for its European operations. Following the establishment of its UK subsidiary, the company is setting up a…
On the afternoon of the 18th, at the Vuori pop-up store in Seongsu-dong, Seongdong-gu, Seoul, a different scene unfolded as I passed through the first and second floors—where clothes were displayed—an…
AprilBio Co.,Ltd.(397030)has decided to explore other indications for “APB-A1” (Lu AG22515), a technology it licensed to Lundbeck, after the compound failed to demonstrate the expected clinical effica…
