[Korea Market Close] KOSPI Plunges to 6,889 as Treasury Yields Breach 5%—Samsung Electronics Slides While HLB Surges on FDA Approval
On September 28, 2026, KOSPI closed at 6,889.74, down 191.24 points or -2.70% , marking its first decline in five trading days. Yet on the same day, twelve HLB-affiliated companies on KOSDAQ hit daily limits. One index segment shed over 5%. The other surged 30%. The market split dramatically within a single session. The explanation is straightforward. U.S. Treasury rates, not company-specific news, drove the broad index. Individual company announcements, not macro trends, moved individual stocks. The two forces operated independently. This created the unusual picture of a falling index accompanied by a dozen limit-up names. U.S. Treasury Yields Moved Alone During the Holiday KOSPI was closed for four trading days over the Chuseok holiday. In that interval, the 10-year U.S. Treasury yield climbed to 5.22%. The 30-year yield exceeded 5.5%—the highest level since 2007. Rising Treasury yields increase borrowing costs for companies that rely on debt to fund growth. Consider t...