[DigitalToday reporter Oh Sang-yup (오상엽)] South Korea's KOSPI slumped more than 3 percent in early trading, falling to the 5,700 level. U.S. tech shares weakened amid worries over Alphabet's weak results and AI investment costs, while profit-taking has emerged in large-cap domestic semiconductor shares that had recently rebounded sharply.

As of 9:11 a.m. on Oct. 30, the KOSPI was down 227.37 points, or 3.83 percent, from the previous session at 5,710.29. The index opened down 177.31 points, or 2.99 percent, at 5,760.35 and widened losses.

By investor type, foreigners and institutions were net sellers of 72.2 billion won and 88.3 billion won, respectively. Retail investors were net buyers of 141.8 billion won, absorbing supply.

Most of the top market-cap stocks were lower.

Samsung Electronics was trading down 3.77 percent from the previous session at 223,250 won, while SK Hynix was down 6.88 percent at 1,421,000 won.

Other semiconductor-related stocks also posted steep declines, including SK Square, down 4.41 percent, and Samsung Electro-Mechanics, down 7.12 percent. LG Energy Solution fell 1.26 percent, Samsung Biologics slipped 0.59 percent, Hyundai Motor lost 2.91 percent, KB Financial Group fell 2.49 percent and Samsung Life dropped 3.60 percent.

The KOSDAQ also fell in tandem. At the same time, the KOSDAQ was down 23.92 points, or 3.18 percent, from the previous session at 729.31.

In Seoul's foreign exchange market, the won was at 1,338.40 per dollar, up 2.10 won from the previous session.

In the U.S. stock market a day earlier, Alphabet's earnings missed market expectations and a sharp increase in AI-related investment costs weighed on sentiment. Alphabet shares plunged 12.6 percent, and the tech-heavy Nasdaq index fell 1.37 percent. Semiconductor shares also slipped 1.4 percent, ending a four-session winning streak.

Large technology shares including Microsoft, as well as semiconductor shares such as Nvidia, AMD and Broadcom, also weakened. Caution appeared to grow again over the pace at which AI investment turns into actual profits and the burden of large-scale capital spending.

South Korea's stock market is also seeing selling expand around semiconductors as U.S. AI tech shares weaken while price 부담 remains high after a recent surge.

Han Ji-young (한지영), a researcher at Kiwoom Securities, said: "Today the domestic market is also expected to open lower on the impact of Alphabet's sharp share drop in the U.S. regular session and, despite AI surprise news from semiconductors and SanDisk, the impact of sharp after-hours declines in Amazon and Intel. After that, during the session it is expected to continue a differentiated market across stocks depending on individual earnings, such as Hyundai Engineering & Construction, Kia and APR."