South Korean stocks closed slightly higher on January 30, extending their winning streak to four sessions and hitting a new record high as investors bought artificial intelligence shares despite bubble concerns. The advance was capped by U.S. President Donald Trump's vow to impose higher tariffs on South Korea. The Korean won fell 13.2 won to 1,439.5 against the U.S. dollar.
The benchmark Korea Composite Stock Price Index (KOSPI) rose 3.11 points, or 0.06 percent, to close at 5,224.3, after touching an intraday high of 5,321.68. The gains were tempered by U.S. President Donald Trump's pledge this week to reinstate 'reciprocal' tariffs and raise auto duties on South Korea to 25 percent. Trading volume was robust at 852 million shares valued at 34.7 trillion won ($24.1 billion), with decliners outnumbering advancers 602 to 278.
Retail investors net bought 2.2 trillion won worth of shares, offsetting net sales of 1.9 trillion won by foreigners and 425 billion won by institutions. Despite bubble worries, investors piled into tech stocks buoyed by strong earnings in the AI cycle. 'For the time being, AI hardware and software companies need to overcome concerns over their profitability,' said Han Ji-young, a researcher at Kiwoom Securities. 'During the period, the market's preference for chipmakers that sell memory products to such companies will remain strong,' Han added.
Market heavyweight Samsung Electronics dipped 0.12 percent to 160,500 won, while SK hynix surged 5.57 percent to a new high of 909,000 won. Brokerages rallied, with Mirae Asset Securities up 4.65 percent to 42,750 won and Kiwoom Securities gaining 4.11 percent to 443,500 won. SK Telecom climbed 4.32 percent to 72,500 won on an improved outlook, and KT rose 1.43 percent to 56,900 won. Samsung SDI edged up 0.52 percent after announcing a battery supply contract, widely seen as linked to Tesla Inc.'s energy storage system business.
Bond prices fell, with the yield on three-year Treasurys rising 3.2 basis points to 3.138 percent and the five-year note up 4.1 basis points to 3.436 percent. The rally underscores tech resilience amid AI demand but highlights vulnerabilities from escalating U.S. trade tensions.
