In Korea’s regular trading session on August 31, 2026, the KOSPI rose 31.14 points (+0.46%) from the previous trading day to 6,820.02 points, while the KOSDAQ fell 4.12 points (-0.49%) to 834.29 points. All four tracked stocks closed higher, with SK hynix and Samsung Electronics in particular posting gains that exceeded the KOSPI’s increase on the same trading day.

Index August 31, 2026 regular-session close Change from previous trading day
KOSPI 6,820.02 points +31.14 points (+0.46%)
KOSDAQ 834.29 points -4.12 points (-0.49%)

KOSPI and KOSDAQ closed in opposite directions after intraday swings

The KOSPI opened at 6,613.58 points in the regular session on August 31, 2026, rose as high as 6,820.10 points intraday, fell as low as 6,547.76 points, and closed at 6,820.02 points. The close was 0.08 points below the intraday high and was higher than the previous trading day’s close. KOSPI closing data for August 31, 2026

The KOSDAQ opened at 821.67 points in the regular session on August 31, 2026, recorded an intraday high of 835.50 points and a low of 805.14 points, and closed at 834.29 points. The close was 12.62 points above the opening level but was down 0.49% from the previous trading day. It can be confirmed that the two indices closed in different directions, but this one day of simultaneous movement alone cannot identify sector- or flow-specific causes. KOSDAQ closing data for August 31, 2026

SK hynix and Samsung Electronics outperformed the KOSPI

SK hynix closed at 1,674,000 won on August 31, 2026, up 21,000 won (+1.27%) from the previous trading day. Its gain was 0.81 percentage points higher than the KOSPI’s +0.46% gain on the same trading day. It opened at 1,678,000 won, reached an intraday high of 1,678,000 won and a low of 1,577,000 won, with volume of 5,371,432 shares. The close was 4,000 won below both the opening price and intraday high, but it was the largest gain among the tracked stocks versus the previous trading day. SK hynix closing data for August 31, 2026 and the SK hynix stock hub provide access to previous analysis.

Samsung Electronics rose 3,000 won (+1.17%) from the previous trading day to 260,000 won on August 31, 2026. Its relative performance gap versus the KOSPI was +0.71 percentage points. It opened at 256,000 won, recorded an intraday high equal to the closing price of 260,000 won, and a low of 246,000 won, with volume of 25,467,200 shares. Closing data confirms that the close matched the intraday high, but this alone cannot determine the cause of trading near the close or the subsequent direction. Samsung Electronics closing data for August 31, 2026 and the Samsung Electronics stock hub can be reviewed together.

Hyundai Motor and SK Square also posted gains above the index

Hyundai Motor rose 4,000 won (+1.00%) from the previous trading day to 403,500 won on August 31, 2026. It recorded a regular-session opening price of 399,500 won, an intraday high of 405,500 won, a low of 387,000 won, and volume of 925,437 shares, while the close was 4,000 won above the opening price. It can be compared with the KOSPI as moving in the same upward direction on the same trading day, with a gain 0.54 percentage points higher, but this does not indicate a causal relationship between the two movements. Hyundai Motor closing data for August 31, 2026 and the Hyundai Motor stock hub provide previous analysis of the individual stock.

SK Square rose 9,000 won (+0.88%) from the previous trading day to 1,037,000 won on August 31, 2026. It opened at 1,021,000 won, reached an intraday high of 1,046,000 won and a low of 974,000 won, with volume of 749,782 shares. The close was 16,000 won above the opening price and 9,000 won below the intraday high. Its gain was 0.42 percentage points higher than the KOSPI’s, which is a relative comparison based on closing prices from the same trading day. SK Square closing data for August 31, 2026 and the SK Square stock hub provide access to previous analysis.

Read negative investor-flow figures separately from pre-market reporting context

Investor-flow data collected on August 31, 2026, listed individuals at -1,454억원, foreign investors at -6,400억원, and institutions at -7,922억원. The fact that all three investor categories were marked with negative figures and that the KOSPI rose +0.46% are results from the same trading day. However, this tally alone cannot support the conclusion that trading by a particular investor group caused the index or individual stock closing prices. Investor-flow data for August 31, 2026

The background presented in news reports should be viewed separately from regular-session closing data. Investing.com’s pre-market report of August 31, 2026, cited U.S. equities and Chairman Kevin Warsh’s hawkish remarks in its headline as context. This is the market interpretation in that report and cannot be established as the direct cause of the KOSPI’s rise or gains in the tracked stocks. Investing.com article

Yonhap News Agency’s pre-market outlook report of August 31, 2026, also cited hawkish remarks by the U.S. Federal Reserve chair in its headline as a source of downward pressure on the KOSPI. The report also identified average daily semiconductor export value in Korea’s exports to be released the following day as an item to watch. These are observations and interpretations in the respective articles, and are not verified merely by their simultaneity with the August 31, 2026 regular-session close. Yonhap News Agency article Article on the next trading day’s observation

Three items to check in the next regular session

  • The next regular-session closing trend can be checked against the KOSPI’s August 31, 2026 close of 6,820.02 points and intraday high of 6,820.10 points, as well as the KOSDAQ’s close of 834.29 points and intraday high of 835.50 points.

  • For the tracked stocks, it is possible to compare how the relative moves of Samsung Electronics +1.17%, SK hynix +1.27%, Hyundai Motor +1.00%, and SK Square +0.88% on August 31, 2026 change in the next regular session. These are observation benchmarks only and do not indicate the following trading day’s direction.

  • It is possible to check how investor-flow figures listed on August 31, 2026—individuals -1,454억원, foreign investors -6,400억원, and institutions -7,922억원—change in the next regular-session tally. Investor flows and closing prices can be compared together, but a causal relationship cannot be established from figures for a single trading day alone.