South Korea's benchmark KOSPI closed 10.8 percent lower at 6,023.66 on July 28 after a steep technology-sector selloff triggered a temporary market-wide trading halt.\n\nThe Korea Exchange activated its circuit-breaker system after the index remained more than 8 percent below the previous close. Under the exchange's rules, that first threshold pauses trading to give investors time to assess a rapid decline. The halt is a volatility safeguard, not a finding that any company or trade was improper.\n\nSamsung Electronics fell 13.4 percent and SK Hynix declined 14.7 percent, according to closing figures reported by The Associated Press. Japan's Nikkei 225 also fell about 4 percent, while other Asian technology markets weakened.\n\nAnalysts cited renewed concern about the durability and financing of the artificial-intelligence investment boom, alongside competitive pressure in semiconductor manufacturing. Those explanations are market assessments rather than confirmed causes of every trade, and prices can change materially in the next session.\n\nSource: Korea Exchange circuit-breaker rules — https://regulation.krx.co.kr/contents/RGL/03/03010402/RGL03010402.jsp\n\nSource: Yonhap News Agency — https://en.yna.co.kr/view/AEN20260728003200320\n\nSource: Associated Press — https://apnews.com/article/a880057323bd065c325ad19b23de0cf3