During South Korea’s regular market session on July 31, 2026, the KOSPI surged 17.91% and the KOSDAQ jumped 11.63%. Among the stocks tracked, SK hynix and SK Square gained 29.95% and 29.91%, respectively, while Samsung Electronics rose 26.81%, with strength in major semiconductor-related stocks occurring alongside the index gains.

KOSPI Closes at 6,595.45 Points, KOSDAQ at 719.76 Points

Index July 31, 2026 Close July 31, 2026 Change
KOSPI 6,595.45 points +1,001.89 points (+17.91%)
KOSDAQ 719.76 points +74.98 points (+11.63%)

The KOSPI closed the regular session on July 31, 2026, at 6,595.45 points, up 1,001.89 points, or 17.91%. On the same trading day, it opened at 5,657.79 points, reached an intraday high of 6,630.77 points, and recorded an intraday low of 5,629.76 points. The close was 937.66 points above the open and 35.32 points below the intraday high. The gap between the intraday high and low was 1,001.01 points. KOSPI closing data

The KOSDAQ closed the regular session on July 31, 2026, at 719.76 points, rising 74.98 points, or 11.63%. On the same trading day, it opened at 666.47 points, reached an intraday high of 723.56 points, and recorded an intraday low of 663.25 points. The close was 53.29 points above the open and 3.80 points below the intraday high. KOSDAQ closing data

On July 31, 2026, the KOSPI’s gain exceeded the KOSDAQ’s by 6.28 percentage points. The open, high, low, and close show that both indexes finished near their daily highs. However, this is an editorial interpretation of the price structure indicating that the day’s upward momentum continued through the regular-session close; it is not evidence explaining the cause of the gains.

SK hynix and SK Square Rise Nearly 30%

SK hynix closed the regular session on July 31, 2026, at 1,718,000 won, up 396,000 won, or 29.95%. On the same trading day, it opened at 1,500,000 won and recorded an intraday low of 1,491,000 won, while the closing price matched the intraday high of 1,718,000 won. Trading volume on July 31, 2026, was 17,597,651 shares. Its gain exceeded the KOSPI’s by 12.04 percentage points and the KOSDAQ’s by 18.32 percentage points on the same day. SK hynix closing data Previous analysis is available through the SK hynix stock hub.

SK Square closed the regular session on July 31, 2026, at 1,038,000 won, rising 239,000 won, or 29.91%. On the same trading day, both the opening price and intraday low were 878,000 won, while the closing price matched the intraday high of 1,038,000 won. Trading volume on July 31, 2026, was 1,588,517 shares. SK Square closing data Related stock records are available through the SK Square stock hub.

Closing data confirm that both stocks finished at their regular-session highs on July 31, 2026, with gains close to 30%. However, their simultaneous gains alone do not establish that one stock drove up the price of the other or that the same catalyst accounted for their entire gains.

Samsung Electronics Also Rises 26.81% as Foreign and Institutional Investors Post Net Purchases

Samsung Electronics closed the regular session on July 31, 2026, at 262,500 won, up 55,500 won, or 26.81%. On the same trading day, it opened at 225,500 won, reached an intraday high of 267,000 won, recorded an intraday low of 224,000 won, and posted trading volume of 107,391,577 shares. The close was 37,000 won above the open but 4,500 won below the intraday high. Samsung Electronics closing data Previous analysis is compiled in the Samsung Electronics stock hub.

Hyundai Motor closed the regular session on July 31, 2026, at 388,000 won, rising 37,000 won, or 10.54%. On the same trading day, both the opening price and intraday low were 362,500 won, while the intraday high was 391,500 won. Trading volume on July 31, 2026, was 1,918,101 shares. Hyundai Motor also posted a double-digit gain, but its return was 7.37 percentage points below the KOSPI’s, representing the largest divergence from the broader market among the stocks tracked. This is only a comparison of relative gains and does not mean that Hyundai Motor had a separate cause of weakness. Hyundai Motor closing data Its previous performance is available through the Hyundai Motor stock hub.

Investor trading data for July 31, 2026, showed net purchases of 72,414 hundred million won by foreign investors and 11,396 hundred million won by institutional investors, while individual investors posted net sales of 82,739 hundred million won. Foreign and institutional net purchases and individual net sales occurred on the same trading day as the index surge, but these figures alone cannot explain the full index gain or the movements of individual stocks. Investor trading data

Yonhap News Agency reported that the July 31, 2026, rebound came as semiconductor investment sentiment improved following three days of steep declines, while also noting caution over whether the rebound could continue. This is the market interpretation presented in the report; closing data alone cannot establish that improved semiconductor investment sentiment directly produced the KOSPI’s 17.91% gain that day. Original Yonhap News Agency report

A separate report stated that gains in semiconductor stocks led the previous US market rebound and that the Philadelphia Semiconductor Index rose 8.19%. The rebound in US semiconductor stocks is reported background that can be considered alongside the strength of South Korean semiconductor stocks, but simultaneous movements in the two markets should not be treated as proof of causation. Original report on the US semiconductor market

Three Items to Watch in the Next Regular Session

  • It will be necessary to check where the KOSPI closes relative to its July 31, 2026, close of 6,595.45 points and intraday high of 6,630.77 points. For the KOSDAQ, another item to monitor is how the gap between the same trading day’s close of 719.76 points and intraday high of 723.56 points changes during the next regular session.

  • It will be important to examine how SK hynix’s July 31, 2026, gain of 29.95%, SK Square’s 29.91% gain on the same trading day, and Samsung Electronics’ 26.81% gain compare with the KOSPI and KOSDAQ during the next regular session. Whether their gap with Hyundai Motor’s July 31, 2026, gain of 10.54% persists is also relevant when comparing volatility across stocks.

  • It will be necessary to check whether the July 31, 2026, direction of foreign net purchases of 72,414 hundred million won, institutional net purchases of 11,396 hundred million won, and individual net sales of 82,739 hundred million won continues in the next regular session. This is not a basis for predicting the next trading day’s direction or recommending trades, but an item for observing the relationship between closing prices and investor trading flows following sharp price changes.