KOSPI Plunges 3.65% as Tech Sell-Off and Oil Risks Hit Seoul Market

South Korean stocks fell sharply on Monday, with the benchmark KOSPI losing 3.65 percent as technology shares came under heavy selling pressure and investors weighed the inflationary threat from elevated oil prices. The decline marked a fourth consecutive losing session for the Seoul market.

The KOSPI closed down 241.69 points at 6,384.24 after opening just 0.07 percent lower and widening its losses through the session. Market breadth was decisively negative: 717 shares declined and 166 advanced. Turnover reached 313 million shares valued at 21.33 trillion won, or about $16 billion.

Foreign investors were the largest net sellers, unloading 2.02 trillion won of shares. Institutional investors sold a net 110.65 billion won, while retail investors absorbed part of the pressure with net purchases of 1.47 trillion won. The imbalance underscored the role of overseas flows in the market's steep retreat.

The heaviest losses were concentrated in technology and other major index components. Samsung Electronics dropped 4.39 percent to 250,500 won, while SK hynix fell 4.52 percent to 1.6 million won. Hana Securities analyst Lim Seung-mi attributed the broader slide in part to the rebalancing of semiconductor-focused exchange-traded funds and concerns that the two chipmakers may have completed treasury-share purchases.

Weakness extended beyond semiconductors. Hanwha Aerospace declined 3.25 percent to 862,000 won, and Hyundai Motor lost 1.39 percent to 320,000 won. Some defensive and transport-related shares moved against the market: shipping company HMM rose 4.81 percent to 21,800 won, while KT&G gained 1.58 percent to 180,200 won.

Investors were also monitoring higher crude prices after renewed Houthi attacks on Saudi Arabia's main airport over the weekend intensified tensions in the Middle East. The prospect of wider disruption to energy supplies added to inflation concerns and raised questions about the path of U.S. monetary policy.

Despite the equity sell-off, the South Korean won strengthened. It was quoted at 1,335.1 won per U.S. dollar at 3:30 p.m., compared with 1,342.8 won at the previous session's close. Government bonds also gained as yields fell. The three-year Treasury yield declined 6.2 basis points to 3.921 percent, while the five-year yield dropped 5.7 basis points to 4.101 percent.