Suspension of programmed purchases
The Seoul stock exchange closed Tuesday's session sharply higher, with the benchmark Kospi index up 168.87 points, or 3.09%, at 5,638.34. According to The Korea Herald, technology stocks were the main support for the market, amid renewed optimism about artificial intelligence and falling oil prices. On the same day, the Korean won strengthened against the dollar.
The sidecar and buying flows
The market rally, fueled by heavy foreign buying, led the Korea Exchange to activate a buy-side sidecar at 10:13, suspending for five minutes buy orders in program trading on Kospi-listed stocks. The source specifies that this was the first such intervention in four sessions. The mechanism triggers when Kospi 200 futures rise by at least 5% and remain at that level for a minute or more.
End-of-day data indicate trading in 183.13 million shares, worth 15.29 trillion won (about $11.55 billion), with 593 stocks rising against 274 falling. Foreign and institutional investors were net buyers of 592.97 billion and 280.38 billion won, respectively, while individual investors were net sellers of 947.78 billion.
What remains to be verified
Samsung Electronics, the market's bellwether stock, gained 4.23% to 222,000 won, while SK hynix rose 5.18% to 1.34 million won. SK Square, the parent company of SK hynix, marked a gain of 7.67% to 828,000 won, and Samsung Electro-Mechanics a gain of 7.42% to 1.2 million won. Lee Kyoung-min, an analyst at Daishin Securities, said foreign and institutional investors had bought major semiconductor stocks en masse thanks to renewed sentiment on AI investments, despite persistent macroeconomic concerns.
On the international front, the source cites gains in major US markets overnight: Dow Jones +0.28%, S&P 500 +0.7% and Nasdaq Composite +0.82%. The improvement in sentiment was attributed to the disclosure by AI startup Anthropic of strong revenue growth in its document for a US listing, which rekindled interest in artificial intelligence-related stocks ahead of big tech earnings and the Federal Reserve's rate decision. The fall in oil, meanwhile, is linked to hopes of easing tensions in the Middle East, after reports of Qatari mediation efforts involving Iran and the United States.
The material does not clarify the extent of Anthropic's revenue growth or the details of the offering, and does not quantify the actual impact of the oil news on energy prices. It also does not indicate market expectations for Fed rates or the possible lasting effects of the rally beyond the single session. The picture offered therefore remains limited to the dynamics of a single trading day.
