In South Korea’s regular trading session on August 11, 2026, the KOSPI closed at 6,345.53 points, up 45.87 points, or 0.73%, from the previous session, outperforming the KOSDAQ’s 0.39% gain. Among the stocks tracked, Samsung Electronics surged 4.13%, while Hyundai Motor fell 1.23%, showing a clear divergence among individual stocks despite the broader market advance. Final investor-flow data showed net purchases of 443 hundred million won by foreign investors and 305 hundred million won by institutions, while retail investors recorded net sales of 707 hundred million won.

KOSPI Outperforms as Both Indexes Retreat From Their Highs

Index August 11, 2026 Regular-Session Close August 11, 2026 Change
KOSPI 6,345.53 points +45.87 points (+0.73%)
KOSDAQ 857.84 points +3.37 points (+0.39%)

The KOSPI opened the August 11, 2026 regular session at 6,240.06 points, fell as low as 6,213.78 points, climbed as high as 6,405.81 points, and closed at 6,345.53 points. The August 11, 2026 closing level was 105.47 points above the opening level but 60.28 points below the session high. The gap between the day’s high and low was 192.03 points. The index gained 45.87 points, or 0.73%, from the previous session. KOSPI closing data

The KOSDAQ opened at 848.59 points on August 11, 2026, traded between 840.45 points and 875.16 points, and ended the regular session at 857.84 points. The August 11, 2026 closing level was 9.25 points above the opening level and 17.32 points below the session high. The gap between the day’s high and low was 34.71 points, and the index rose 3.37 points, or 0.39%, from the previous session. KOSDAQ closing data

Both indexes advanced on August 11, 2026, but the KOSPI’s gain was 0.34 percentage points larger than the KOSDAQ’s. The editorial interpretation based on the closing data is that the KOSPI held the relative advantage that day, in contrast to the KOSDAQ’s notable relative strength in the previous session. However, the difference in percentage performance alone cannot establish the cause of any fund flows or determine the contribution of a particular industry to the indexes.

Samsung Electronics Surges 4.13%, While Hyundai Motor Moves Against the Index

Samsung Electronics closed at 239,500 won on August 11, 2026, up 9,500 won, or 4.13%, from the previous session. It posted the largest percentage gain among the stocks tracked and outperformed the KOSPI’s 0.73% gain in the same session by 3.40 percentage points. The stock opened at 230,000 won, reached a high of 243,000 won and a low of 224,000 won, and recorded regular-session volume of 37,672,855 shares. The closing price was 9,500 won above the opening price and 3,500 won below the session high, retaining a substantial portion of the day’s advance through the close. Samsung Electronics closing data Previous analysis is available at the Samsung Electronics stock hub.

Hyundai Motor ended the August 11, 2026 regular session at 403,000 won, down 5,000 won, or 1.23%, from the previous session. The stock opened at 409,500 won, reached a high of 411,500 won and a low of 400,500 won, and recorded volume of 505,855 shares. The closing price was 6,500 won below the opening price and 2,500 won above the session low. Compared with the KOSPI’s 0.73% gain on August 11, 2026, Hyundai Motor moved in the opposite direction, with a performance gap of minus 1.96 percentage points relative to the KOSPI. Hyundai Motor closing data Related records are available at the Hyundai Motor stock hub.

The fact that Samsung Electronics strengthened while Hyundai Motor weakened during the same regular session is not enough to infer a flow of funds between the two stocks or a common catalyst. The conclusion supported by the data is the relative movement observed on August 11, 2026: Samsung Electronics outperformed the index, while Hyundai Motor closed in the opposite direction.

SK Hynix and SK Square Diverge in Intraday Paths and Changes From the Previous Close

SK Hynix closed at 1,425,000 won on August 11, 2026, up 5,000 won, or 0.35%, from the previous session. The stock opened at 1,401,000 won, reached a high of 1,455,000 won and a low of 1,373,000 won, and recorded regular-session volume of 5,771,880 shares. The closing price was 24,000 won above the opening price but 30,000 won below the session high. Its 0.35% gain on August 11, 2026 was 0.38 percentage points below the KOSPI’s 0.73% gain and 3.78 percentage points below Samsung Electronics’ 4.13% gain. SK Hynix closing data Previous analysis is available at the SK Hynix stock hub.

SK Square ended the August 11, 2026 regular session at 945,000 won, down 4,000 won, or 0.42%, from the previous session. The stock opened at 935,000 won, reached a high of 960,000 won and a low of 901,000 won, and recorded volume of 665,151 shares. Although it declined from the previous session, its August 11, 2026 closing price was 10,000 won above the day’s opening price. The gap between the session high and low was 59,000 won, and the closing price was 15,000 won below the high. SK Square closing data Historical stock-specific trends are available at the SK Square stock hub.

Samsung Electronics and SK Hynix both gained on a closing-price basis, but the difference between their August 11, 2026 gains was 3.78 percentage points. The fact that the tracked semiconductor stocks moved in the same direction should therefore be distinguished from any conclusion that the strength of their gains was the same. SK Square also declined from the previous close but rose from its opening price, so the description of its price path differs depending on whether the previous closing price or the day’s opening price is used as the reference point.

Final Net Buying by Foreign Investors and Institutions, and the Reported Intraday Backdrop

Final investor-flow data for August 11, 2026 showed net purchases of 443 hundred million won by foreign investors and 305 hundred million won by institutions. Retail investors recorded net sales of 707 hundred million won in the same session. The final net buying by foreign investors and institutions and final net selling by retail investors coincided with gains of 0.73% in the KOSPI and 0.39% in the KOSDAQ, but this simultaneous movement alone does not establish that investor flows caused the indexes to rise. Investor flow data

Yonhap News Agency’s intraday report on August 11, 2026 cited uncertainty surrounding the Strait of Hormuz as part of the market backdrop and explained that the KOSPI had reversed higher after weakening in early trading. At the time of the report, foreign investors were net buyers while retail investors and institutions were net sellers, but the final data compiled after the regular session showed institutions as net buyers of 305 hundred million won. This reflects the different compilation times of the intraday report and the final investor-flow data, and the intraday direction presented in the article should not be substituted for the closing figures. Original intraday market report

A separate market-opening review published on August 11, 2026 cited the burden of semiconductor companies’ fundraising and profit-taking in the US stock market as part of the backdrop. This was the report’s explanation of US market developments and does not provide a basis for interpreting it as the direct cause of Samsung Electronics’ 4.13% gain in South Korea’s regular session on August 11, 2026. Original market-opening review

Three Items to Check in the Next Regular Session

  • It will be important to check whether the KOSPI narrows the 60.28-point gap between its August 11, 2026 close of 6,345.53 points and that day’s high of 6,405.81 points at the next regular-session close. For the KOSDAQ, the August 11, 2026 close of 857.84 points and high of 875.16 points can serve as comparison points.

  • It will be important to examine how the 3.78-percentage-point gap between Samsung Electronics’ 4.13% gain and SK Hynix’s 0.35% gain on August 11, 2026 changes at the next regular-session close. Hyundai Motor’s 1.23% decline and SK Square’s 0.42% decline on August 11, 2026 also provide reference points for comparing their relative movement against the index.

  • It will be necessary to check whether the direction of foreign investors’ net purchases of 443 hundred million won, institutions’ net purchases of 305 hundred million won, and retail investors’ net sales of 707 hundred million won on August 11, 2026 continues in the next regular session’s final data. This is a comparison item for final investor flows and is not a basis for predicting the direction of the indexes or individual stocks in the next regular session.