During the regular Korean market session (09:00–15:30) on October 20, 2026, the KOSPI fell 215.27 points (3.73%) to 5,552.74 points, while the KOSDAQ declined 26.92 points (3.33%) to 781.97 points. All tracked stocks closed lower, with SK Square and Hyundai Motor posting declines greater than the KOSPI’s. Both indexes closed near their intraday lows, leaving wide gaps between their opens and highs and their closing levels.

Index October 20, 2026 regular-session close Change from previous trading day October 20, 2026 regular-session high·low
KOSPI 5,552.74 points -215.27 points (-3.73%) 5,733.57 points·5,493.24 points
KOSDAQ 781.97 points -26.92 points (-3.33%) 807.22 points·773.32 points

KOSPI Opens at Its High and Settles Near Its Low

During the regular session on October 20, 2026, the KOSPI opened at 5,733.57 points, which was also its intraday high. Its intraday low was 5,493.24 points, and it closed at 5,552.74 points, 59.50 points above that low. The gap between the close and the high was 180.83 points, while the gap between the high and low was 240.33 points. These are facts about the regular-session price range on that trading day; price movement alone cannot determine the cause of the decline. KOSPI regular-session closing data

The KOSDAQ opened at 805.37 points on October 20, 2026, rose to 807.22 points intraday, then fell to 773.32 points before closing at 781.97 points. The close was 8.65 points above the intraday low and 25.25 points below the intraday high. The concurrent declines in the KOSPI and KOSDAQ are confirmed, but same-day movement alone cannot establish a common direct cause. KOSDAQ regular-session closing data

In its headline, Yonhap News cited political instability in France and renewed concerns about AI debt as factors behind the day’s weakness. This is the interpretation presented in the report; the regular-session closing and intraday-range data above do not themselves establish a causal relationship with those factors. Original Yonhap News article

SK Square and Hyundai Motor Fall More Than Samsung Electronics

SK Square closed at 736,000 won on October 20, 2026, down 44,000 won (5.64%). It opened at 794,000 won, reached an intraday high of 799,000 won and a low of 722,000 won, and traded 624,056 shares. Its closing decline was 1.91 percentage points larger than the KOSPI’s 3.73% decline on the same trading day, and the difference between its intraday high and low was 77,000 won. Historical analysis is available through SK Square closing data and the SK Square stock hub.

Hyundai Motor fell 16,500 won (5.06%) to 309,500 won on October 20, 2026. It recorded an open of 323,000 won, an intraday high of 326,000 won, a low of 305,500 won, and trading volume of 679,895 shares. Its decline was 1.33 percentage points larger than the KOSPI’s on the same trading day. This is a comparison of closing-price performance only and does not indicate the cause of the difference in declines. See Hyundai Motor closing data and the Hyundai Motor stock hub.

SK hynix fell 62,000 won (4.86%) to 1,215,000 won on October 20, 2026, while Samsung Electronics fell 6,000 won (2.75%) to 212,000 won. SK hynix’s decline was 1.13 percentage points larger than the KOSPI’s, while Samsung Electronics’ decline was 0.98 percentage points smaller. The fact that both stocks closed lower and the differences in their individual price changes alone cannot establish sector- or company-specific causes. Details are available through SK hynix closing data·SK hynix stock hub and Samsung Electronics closing data·Samsung Electronics stock hub.

Closing Data Shows Net Buying by Individuals and Net Selling by Foreign Investors and Institutions

As of the October 20, 2026 close, net trading by investor group totaled individuals +8,971 hundred million won, foreign investors -5,348 hundred million won, and institutions -9,975 hundred million won. Individuals were recorded as net buyers, while foreign investors and institutions were recorded as net sellers. These investor-flow figures can be viewed alongside the same-day closing changes of -3.73% for the KOSPI and -3.33% for the KOSDAQ, but a single day’s net trading data cannot determine that trading by any investor group directly caused the index declines. October 20, 2026 investor-flow data

An intraday report by NewsPim also described selling dominance by foreign investors and institutions alongside the day’s weak market conditions. However, the article covered market conditions while the regular session was still in progress, so it should be read separately from the October 20, 2026 closing investor flows and the 15:30 closing prices used in this article. Original NewsPim article

Three Items to Check in the Next Regular Session

  • Compare the October 20, 2026 KOSPI close of 5,552.74 points and intraday low of 5,493.24 points, as well as the KOSDAQ close of 781.97 points and intraday low of 773.32 points, with the next regular-session close. KOSPI data KOSDAQ data

  • Check how the closing price changes of tracked stocks—SK Square -5.64%, Hyundai Motor -5.06%, SK hynix -4.86%, and Samsung Electronics -2.75% on October 20, 2026—change in the next regular session. SK Square data Hyundai Motor data SK hynix data Samsung Electronics data

  • Review how net trading by investor group—individuals +8,971 hundred million won, foreign investors -5,348 hundred million won, and institutions -9,975 hundred million won as of the October 20, 2026 close—moves alongside index closing prices in the next regular-session data. Investor-flow data