In South Korea’s regular trading session on August 5, 2026, the KOSPI rose 3.76% to 6,598.26 points, outperforming the KOSDAQ’s 2.42% gain by 1.34 percentage points. All tracked stocks rose, with SK hynix and SK Square gaining 5.77% and 5.57%, respectively, and posting stronger closing performances than the large-cap-driven KOSPI.

KOSPI Gains 239.31 Points, KOSDAQ Closes at the 799 Level

Index August 5, 2026 Close August 5, 2026 Change
KOSPI 6,598.26 points +239.31 points (+3.76%)
KOSDAQ 799.59 points +18.87 points (+2.42%)

The KOSPI closed the August 5, 2026 regular session from 09:00 to 15:30 at 6,598.26 points, up 239.31 points, or 3.76%, from the previous trading day. During the same session, it opened at 6,603.48 points, reached a high of 6,674.66 points and fell to a low of 6,540.27 points. The close was 5.22 points below the open and 76.40 points below the high, while remaining 57.99 points above the low. The difference between the regular-session high and low on August 5, 2026 was 134.39 points. KOSPI closing data

The KOSDAQ closed the August 5, 2026 regular session at 799.59 points, up 18.87 points, or 2.42%, from the previous trading day. It opened at 794.93 points, reached a high of 803.49 points and fell to a low of 783.32 points. The close was 4.66 points above the open and 3.90 points below the high, leaving the index relatively close to its regular-session high at the end of trading. The difference between the high and low on August 5, 2026 was 20.17 points. KOSDAQ closing data

The KOSPI closed below its opening level, while the KOSDAQ closed above its opening level. This is a comparison of the two indexes’ intraday price paths during the August 5, 2026 regular session and does not indicate what caused their gains or their direction on the next trading day.

SK hynix and SK Square Outperform the KOSPI

SK hynix closed the August 5, 2026 regular session at KRW 1,668,000, up KRW 91,000, or 5.77%, from the previous trading day. It posted the largest percentage gain among the tracked stocks and outperformed the KOSPI’s 3.76% gain that day by 2.01 percentage points. It opened at KRW 1,652,000, reached a high of KRW 1,701,000 and fell to a low of KRW 1,647,000, with trading volume of 6,660,184 shares. The close was KRW 16,000 above the open and KRW 33,000 below the regular-session high. SK hynix closing data Previous coverage is available in the SK hynix stock hub.

SK Square closed the August 5, 2026 regular session at KRW 1,119,000, up KRW 59,000, or 5.57%, from the previous trading day. Its gain was 1.81 percentage points higher than the KOSPI’s advance that day. It opened at KRW 1,150,000, reached a high of KRW 1,182,000 and fell to a low of KRW 1,105,000, with trading volume of 1,002,022 shares. The close was KRW 31,000 below the open and KRW 63,000 below the high, meaning the stock retreated from its intraday peak despite its strong daily gain. SK Square closing data Related coverage is compiled in the SK Square stock hub.

The fact that SK hynix and SK Square both posted gains in the 5% range on August 5, 2026 does not by itself establish that the same catalyst drove both stocks higher. The closing data directly show that the difference between their gains was only 0.20 percentage points on August 5, 2026 and that both outperformed the KOSPI.

Samsung Electronics and Hyundai Motor Also Rise but Trail the Index

Samsung Electronics closed the August 5, 2026 regular session at KRW 246,000, up KRW 6,000, or 2.50%, from the previous trading day. It opened at KRW 250,000, reached a high of KRW 254,500 and fell to a low of KRW 244,000, with trading volume of 38,790,130 shares. The close was KRW 4,000 below the open and KRW 2,000 above the low. The stock moved in the same direction as the KOSPI, but its gain was 1.26 percentage points lower than the index’s advance on August 5, 2026. Samsung Electronics closing data Previous analysis of the stock is available in the Samsung Electronics stock hub.

Hyundai Motor closed the August 5, 2026 regular session at KRW 404,500, up KRW 12,000, or 3.06%, from the previous trading day. Both its open and low were KRW 400,000, while its high was KRW 411,000 and trading volume was 927,725 shares. The close was KRW 4,500 above the open, but its gain was 0.70 percentage points lower than the KOSPI’s advance that day. Hyundai Motor closing data Previous coverage is available in the Hyundai Motor stock hub.

From an editorial perspective, the August 5, 2026 closing performance of the tracked stocks can be divided between the relative strength of SK hynix and SK Square and the smaller gains of Samsung Electronics and Hyundai Motor compared with the index. This is solely an interpretation based on closing-return comparisons and does not mean that earnings or company-specific catalysts caused the differences.

Foreign Net Buying Should Be Distinguished From Reports of a US-Market Tailwind

Investor-flow data for August 5, 2026 showed foreign investors recording net purchases of KRW 14,463 hundred million. Retail investors posted net sales of KRW 11,834 hundred million that day, while institutional investors posted net sales of KRW 2,838 hundred million. Foreign net buying and gains in the KOSPI and KOSDAQ were observed on the same trading day, but that simultaneous movement alone does not establish that foreign purchases produced the indexes’ gains. Investor flow data

Yonhap News cited a “tailwind from US markets” as a factor behind the strength of South Korea’s stock market on August 5, 2026. In a separate premarket report, Yonhap explained that overnight gains in US stocks and a rise in SK hynix’s ADR helped draw attention to South Korea’s large semiconductor stocks. These were market interpretations presented in the reports, not causal relationships established solely by South Korean closing data. Original Yonhap intraday report Original Yonhap premarket report

NewsPim’s August 5, 2026 market-opening report also cited strength in US semiconductor stocks as a factor behind South Korea’s early-session gains. However, opening prices and investor trading activity at that point should be distinguished from the final investor flows and regular-session closing data recorded at 15:30 on August 5, 2026. The report can therefore be viewed as context for the market’s tone that day, but it is not evidence establishing the cause of the KOSPI’s 3.76% closing gain or SK hynix’s 5.77% advance. Original NewsPim opening-market report

Three Items to Check in the Next Regular Session

  • It will be necessary to examine whether the KOSPI narrows, at a subsequent regular-session close, the 76.40-point gap between its August 5, 2026 close of 6,598.26 points and regular-session high of 6,674.66 points. For the KOSDAQ, its August 5, 2026 close of 799.59 points and high of 803.49 points can serve as comparison levels.

  • The 5.77% and 5.57% gains posted by SK hynix and SK Square on August 5, 2026 should be compared with Samsung Electronics’ 2.50% gain and Hyundai Motor’s 3.06% gain in subsequent regular sessions. This is a benchmark for retrospectively comparing the stocks’ relative movements, not for making buy-or-sell decisions or predicting direction.

  • It will be necessary to check whether the August 5, 2026 direction of foreign net purchases of KRW 14,463 hundred million, retail net sales of KRW 11,834 hundred million and institutional net sales of KRW 2,838 hundred million continues in subsequent regular sessions, as well as how those flows relate to closing-price movements. Even if investor flows and prices move in the same direction, that fact alone does not establish causation.