KOSPI Plunges Nearly 7 Percent Below 5,950 as Foreign Selling Hits Samsung and SK Hynix

SEOUL — The KOSPI fell nearly 7 percent by late morning Tuesday, dropping below 5,950 and extending a foreign-led sell-off in chip stocks that began after a Chinese memory maker said it would ship a denser server product this year.

The index was at 5,940.48 at 11:53 a.m., down 443.76 points, or 6.95 percent, from Monday's close of 6,384.24. It opened 3.1 percent lower. Yonhap reported it at 5,997.99, down 6.05 percent, at 11:20 a.m. A sell sidecar, which temporarily suspends program sell orders, was triggered at 9:47 a.m. when the index was down more than 5 percent. The print is still mid-session.

Samsung Electronics was down about 7.3 percent and SK Hynix about 8.4 percent in the Yonhap snapshot. Hanwha Aerospace fell 5.34 percent and Hyundai Motor 5.78 percent. Foreign investors had sold a net 2.3 trillion won ($1.7 billion) by 11:20 a.m. Institutions bought a net 808.9 billion won and individuals 1.27 trillion won. The won was at 1,339.45 to the dollar.

The selling followed weekend remarks by ChangXin Memory Technologies president Cao Kanyu that the Chinese firm had made progress on a 4F² cell design and planned a server DDR5 module by year-end. The structure can cut cell area by about a third versus the industry-standard 6F² layout. Samsung, SK Hynix and Micron have pursued the same architecture; Samsung has targeted mass production around 2028. Overnight the Philadelphia Semiconductor Index fell, and U.S. stocks were mixed, with the Nasdaq down 0.44 percent. Investors are also awaiting Wednesday's U.S. consumer-price report.

Monday's close was already down 3.65 percent at 6,384.24, the steepest single-day drop since Sept. 2. Foreigners sold a net 2.02 trillion won that day. Hana Securities analyst Lim Seung-mi said the Monday decline came "amid rebalancing of semiconductor-focused exchange-traded funds (ETFs) and concerns that Samsung Electronics and SK hynix may have completed their treasury stock purchases." Tuesday's open extended that flow.

A nearly 7 percent morning drop on no new Korean earnings number is a valuation reset on two stocks that dominate the index. The CXMT date is a schedule, not a yield. The foreign outflow is a fact. The sidecar is a fact. Whether 5,940 holds into the close depends on whether the same sellers are still active after lunch.