The Kospi fell 0.71% to 6,793.38 at 9:26 a.m. on Oct. 1, the first trading day of October, as foreign investors and institutions sold a combined net 500 billion won. Retail investors bought 389.9 billion won but could not prevent the decline. Samsung Electronics and SK Hynix fell 1.02% and 1.13%, respectively, as sentiment toward chip stocks weakened after Micron Technology’s earnings and rising U.S. Treasury yields pressured equities. Micron beat market consensus but missed the unofficial whisper number, while its shares were little changed in after-hours trading. The 10-year Treasury yield rose above 5.3%, its highest level since May 2002, and the 30-year yield exceeded 5.6%, its highest since June 2002. The Kosdaq rose 0.56% to 860.99, supported by net buying from retail and foreign investors. South Korean stocks followed mixed trading on Sept. 30 in the United States, where the Dow and S&P 500 fell while the Nasdaq Composite gained.