Where did the foreign investors who were aggressively buying go… After hitting 7,200 points, they sold off rapidly; a 'rebound' has now been attached to this.

As foreign net buying pressure subsided, KOSPI's streak of consecutive closing gains ended after five trading days. This was due to heightened risk-aversion sentiment amid geopolitical tensions originating from the Middle East and a broad rise in long-term U.S. Treasury yields. Experts say attention should be focused on international oil prices and market interest rate trends following the release of the Federal Open Market Committee (FOMC) minutes for July, scheduled for tomorrow, the 19th.

On the 18th, KOSPI closed at 6,869.83, down 108.11 points (1.55%) from the previous trading day. Earlier in the session, KOSPI rose to as high as 7,216.62, recovering to the 7,200 level before falling back to the 6,800 level.

The securities industry points to geopolitical uncertainty stemming from the Middle East and rising U.S. Treasury yields as factors that pulled down the KOSPI index. On the 17th (local time), the 60th-day negotiation period for the peace memorandum of understanding (MOU) signed between the United States and Iran in June expired, yet both sides announced their refusal to extend it. Especially, U.S. President Donald Trump stated in an interview with the media that "if Oman interferes in negotiations with Iran, I will bomb them without mercy." As concerns over energy supply and demand resurfaced, Brent crude oil futures for October delivery on the London ICE Futures Exchange closed above $90 per barrel.

Amid growing caution about inflation (rising prices), international oil prices rose again, pushing U.S. 30-year Treasury yields to their highest level in 19 years since June 2007. The yield on U.S. 30-year Treasuries reached 5.31%, while the 10th-year Treasury yield rose to 4.728%.

Lee Sang-yeon, a researcher at Shinhan Securities, analyzed: "During the domestic holiday period, some stocks centered on memory semiconductors such as U.S.-based Micron, Japan's Kioxia, and China's CXMT (Changxin Memory Technologies) rose." He added, "In the domestic stock market, buying orders focused on Samsung Electronics and SK Hynix semiconductor stocks entered the market early in the session."

He further noted, "As yields on government bonds rose in major countries including the United States, Japan, and Europe, profit-taking sales emerged during trading hours."

On this day, institutional investors sold 784.9 billion won worth of stocks in the KOSPI market (based on Korea Exchange data). Retail investors and foreign investors bought 731.2 billion won and 86 billion won worth of stocks, respectively. Foreign investors, who had continued net buying for four consecutive trading days until the previous session, also initiated net purchases exceeding 1 trillion won early in the session but reduced their net buying volume during trading hours.

Among KOSPI sectors, IT (information and communications) services closed with a decline of over 5%. Securities fell more than 4%, while machinery & equipment, transportation equipment & parts, and construction dropped by over 3%. Pharmaceuticals declined by over 2%. Electricity & gas, manufacturing, metals, electrical & electronics, and chemicals each fell by over 1%. Financials and real estate closed roughly flat, while telecommunications closed with a slight gain. Transportation & warehousing rose by over 1%, and insurance climbed by more than 2%.

Among the top KOSPI market capitalization stocks, Samsung Electronics fell sharply by over 7%. LG Energy Solution dropped by more than 5%. Hyundai Motor and Kia each declined by over 3%. Samsung Electronics fell by over 2%, and Samsung Biologics declined by over 1%. SK Square fell by more than 1%, while SK Hynix rose by over 1%. Samsung Life Insurance also rose by over 3%.

The KOSDAQ closed at 834.20, down 30.45 points (3.52%) from the previous trading day.

In the KOSDAQ market, institutional investors sold net 416.4 billion won worth of stocks. Retail investors and foreign investors bought net 389.2 billion won and 36.7 billion won worth of stocks, respectively.

Among KOSDAQ sectors, financials and metals slipped by more than 5%. Non-metals declined by over 4%. Pharmaceuticals, medical & precision instruments, IT services, electrical & electronics, and manufacturing each fell by more than 3%. Food & tobacco, construction, chemicals, and machinery & equipment dropped by around 1%. Distribution closed roughly flat, while telecommunications closed with a slight gain. Textiles & apparel rose by over 4%.

The top four KOSDAQ stocks by market capitalization all fell sharply. EcoPro, EcoPro BM, and Rainbow Robotics each plummeted by more than 6%. Altheagen, the number one stock by market cap, also declined by over 5%. AVL Bio also dropped by more than 5%. Rino Industrial fell by around 4%, and Wonik IPS declined by over 3%. Juseong Engineering closed roughly flat. IOTech rose by more than 2%.

Experts in the financial investment industry forecast that domestic stock market momentum will depend on whether international oil prices and U.S. Treasury yields continue to rise, following the scheduled release of July FOMC minutes tomorrow, the 19th, amid heightened geopolitical tensions.

Im Jeong-eun and Tae Yun-seon, researchers at KB Securities, stated: "After KOSPI experienced a sharp short-term rebound, foreign investors switched to net selling for the first time in five trading days." They added, "As the market enters a phase of speed adjustment, the continuity of the rebound and potential tests of support levels will likely be determined by the FOMC minutes and developments in Middle East politics."

On this day, in Seoul's foreign exchange market, the won-dollar exchange rate closed at 1,411.8 won for weekly trading (3:30 p.m.), down 1.2 won from the previous day's closing price.