South Korea’s Kosdaq plunged nearly 5% in early trading on Friday, Aug. 21, 2026, triggering a sell-side trading curb known locally as a sidecar. The Korea Exchange suspended program sell orders for five minutes from 10:05 a.m. When the measure was activated, Kosdaq 150 futures stood at 1,387.40, down 89.60 points, or 6.06%, from the previous close, while the Kosdaq 150 spot index fell 80.71 points, or 5.48%, to 1,391.11. By 10:10 a.m., the Kosdaq was down 40.52 points, or 4.82%, at 800.37, and its losses later widened beyond 5% during intraday trading. The Kospi fell 52.82 points, or 0.76%, to 6,800.76. Samsung Electronics was trading less than 2% higher, while SK hynix gained more than 3%.