On the 26th, the domestic stock market plunged more than 3% after running into a spoiler: Google's new technology "TurboQuant." TurboQuant is a Google artificial intelligence (AI) model that sharply reduces memory usage, and as concerns grew that new technology could curb memory demand, large-cap semiconductor stocks fell steeply.
The KOSPI closed at 5,460.46, down 181.75 points (3.22%) from the previous session. It initially opened at 5,594 points, down 0.85%, but as shares of Samsung Electronics and SK hynix extended losses, the index slumped below 5,500.
Foreign investors were net sellers of more than 3 trillion won on the main board, and institutions, including pension funds, also showed a selling bias. Only retail investors were net buyers of more than 3 trillion won. Program trading produced 1.6 trillion won in net selling.
On the previous day, as the United States proposed a cease-fire to Iran, expectations grew that geopolitical risk in the Middle East would ease. That helped lift U.S. stocks.
But after Google unveiled "TurboQuant," an advanced quantization algorithm that cuts memory usage for large language models (LLMs) by more than sixfold, investor sentiment toward semiconductors deteriorated sharply. U.S. semiconductor stocks such as Micron and SanDisk fell, and in the domestic market, IT shares—centered on semiconductors—were broadly weaker.
Kang Jin-hyeok, an analyst at Shinhan Investment & Securities, said, "Before the Middle East crisis could be resolved, 'memory noise' erupted," and noted, "In the case of SK hynix, the decision to issue depository receipts (ADR) for a U.S. listing also weighed on the share price." As SK hynix tumbled, SK Square also fell more than 7%.
Hanwha Solutions, which announced a large rights offering during the session, plunged more than 18%. Hanwha Solutions said it decided on a 2.5 trillion won rights offering via a shareholder allocation to fund debt repayment.
After starting slightly higher and rising in early trade, the KOSDAQ turned lower. The KOSDAQ finished at 1,136.64, down 22.91 points (1.98%).
Sam Chun Dang Pharm, which has become the KOSDAQ's "bellwether," rose, and Alteogen also surged, reclaiming the No. 2 spot in market capitalization. Kolon TissueGene also jumped on news that clinical trials for an osteoarthritis treatment would be wrapped up.
By contrast, materials, parts and equipment names fell, including LEENO Industrial, dragging the index down by nearly 2%.