In South Korea’s regular trading session on August 13, 2026, the KOSPI closed at 6,813.34 points, up 234.30 points, or 3.56%, from the previous session. The KOSDAQ gained just 2.46 points, or 0.29%, to 861.37 points in the same session, widening the performance gap between the two indexes to 3.27 percentage points. Among the stocks tracked, SK Square posted the largest gain at 9.08%, while SK hynix and Samsung Electronics also outperformed the KOSPI.
KOSPI Gains 3.56%, Outpacing KOSDAQ by 3.27 Percentage Points
| Index | August 13, 2026 Regular-Session Close | August 13, 2026 Change |
|---|---|---|
| KOSPI | 6,813.34 points | +234.30 points (+3.56%) |
| KOSDAQ | 861.37 points | +2.46 points (+0.29%) |
The KOSPI opened the regular session on August 13, 2026, at 6,773.92 points, traded between 6,748.13 points and 6,895.63 points, and closed at 6,813.34 points. The August 13, 2026 close was 39.42 points above the opening level but 82.29 points below the intraday high. The high-low range for the session was 147.50 points. KOSPI closing data
The KOSDAQ opened at 863.15 points on August 13, 2026, fell as low as 853.09 points and rose as high as 870.96 points before closing at 861.37 points. The close was 1.78 points below the August 13, 2026 opening level and 9.59 points below the high. The high-low range for the session was 17.87 points. KOSDAQ closing data
The editorial interpretation based on the closing data is that the August 13, 2026 rally did not occur with equal strength in both markets. The fact that the KOSPI and KOSDAQ both rose is not, by itself, enough to conclude that a specific factor caused the performance gap between the two indexes.
SK Square Gains 9.08%, the Largest Increase Among Tracked Stocks
SK Square ended the regular session on August 13, 2026, at 1,117,000 won, up 93,000 won, or 9.08%, from the previous session. It outperformed the KOSPI’s 3.56% gain by 5.52 percentage points, posting the strongest increase among the stocks tracked. The stock opened at 1,063,000 won, reached a high of 1,150,000 won and a low of 1,063,000 won, and recorded regular-session volume of 1,125,469 shares. The August 13, 2026 close was 54,000 won above the opening price and 33,000 won below the high. SK Square closing data Previous stock analysis is available through the SK Square stock hub.
SK hynix closed at 1,593,000 won on August 13, 2026, up 89,000 won, or 5.92%, from the previous session. It opened at 1,579,000 won, traded between 1,552,000 won and 1,634,000 won, and recorded volume of 6,985,809 shares. The close was 14,000 won above the August 13, 2026 opening price and 41,000 won below the high. Its gain was 2.36 percentage points greater than the KOSPI’s increase in the same session. SK hynix closing data Previous coverage is compiled in the SK hynix stock hub.
Samsung Electronics Also Outperforms the Index, While Hyundai Motor’s Gain Is Relatively Limited
Samsung Electronics ended the regular session on August 13, 2026, at 268,000 won, up 12,500 won, or 4.89%, from the previous session. It opened at 265,000 won, reached a high of 271,000 won and a low of 260,500 won, and recorded volume of 50,510,542 shares. The close was 3,000 won above the August 13, 2026 opening price and 3,000 won below the high, while its gain exceeded the KOSPI’s by 1.33 percentage points. Samsung Electronics closing data Related analysis is available through the Samsung Electronics stock hub.
Hyundai Motor closed at 418,500 won on August 13, 2026, up 9,000 won, or 2.20%, from the previous session. It opened at 411,500 won, reached a high of 431,500 won and a low of 411,500 won, and recorded regular-session volume of 1,007,645 shares. The close was 7,000 won above the opening price but 13,000 won below the high. Hyundai Motor also advanced, but its August 13, 2026 gain was 1.36 percentage points below the KOSPI’s, making its increase relatively limited among the stocks tracked. Hyundai Motor closing data Previous analysis of the individual stock is available through the Hyundai Motor stock hub.
The editorial interpretation is that the August 13, 2026 gains among the tracked stocks were widely dispersed, ranging from Hyundai Motor’s 2.20% to SK Square’s 9.08%, showing clear differences in performance by stock. However, relative strength or weakness at the close alone cannot establish the reason for a particular stock’s gain or confirm capital rotation between stocks.
Distinguishing Foreign and Institutional Net Buying From CPI Coverage
Final investor-flow data for August 13, 2026 showed net purchases of 21,065 hundred million won by foreign investors and 6,817 hundred million won by institutional investors. Individual investors recorded net sales of 27,356 hundred million won in the same session. Foreign and institutional net buying and individual net selling occurred alongside the KOSPI’s 3.56% gain, but these concurrent movements alone are not enough to conclude that investor flows directly caused the index to rise. August 13, 2026 investor-flow data
A Yonhap News report published before the market opened on August 13, 2026 cited relief over slowing US consumer inflation as context for the domestic stock-market outlook. A MoneyToday report published early in the same session also described favorable US consumer inflation data and the performance of the New York stock market as background for the KOSPI’s higher opening. These were interpretations presented in the articles; South Korea’s August 13, 2026 regular-session closing data does not itself establish those causal relationships. Original Yonhap News article Original MoneyToday article
A NewsPim report published before the market opened on August 13, 2026 cited gains in US semiconductor stocks, easing interest-rate pressure, and expectations that positive sentiment would spread through South Korea’s semiconductor sector as context for the market outlook at the time. At the regular-session close, SK hynix had gained 5.92% and Samsung Electronics 4.89%. However, observing those gains alongside the report is not enough to establish the factors mentioned in the article as definitive causes of the increases. Original NewsPim article
Three Items to Check in the Next Regular Session
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Check whether the KOSPI narrows the 82.29-point gap between its August 13, 2026 close of 6,813.34 points and that session’s high of 6,895.63 points at the next regular-session close. For the KOSDAQ, the comparison is the 9.59-point gap between its August 13, 2026 close of 861.37 points and its high of 870.96 points.
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Watch whether the August 13, 2026 gains of 9.08% for SK Square, 5.92% for SK hynix, and 4.89% for Samsung Electronics continue to show relative strength above the KOSPI’s 3.56% gain at the next regular-session close. The 1.36-percentage-point gap between Hyundai Motor’s August 13, 2026 gain of 2.20% and the KOSPI is also an item to monitor.
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Check how the final August 13, 2026 investor-flow direction—foreign net purchases of 21,065 hundred million won, institutional net purchases of 6,817 hundred million won, and individual net sales of 27,356 hundred million won—changes in the next regular-session data. This is a comparison item and is not a basis for predicting the direction of the index or individual stocks in the next regular session.