South Korean equities experienced a sharp reversal from early highs during Thursday morning trade, with leveraged ETF products tracking major tech names bearing the brunt of the selloff. The CSOP Two Times Long Samsung Electronics (07747) ETF dropped 9.09% to HK$81.8, while the CSOP SK hynix Daily Leveraged (2x) Product (07709) fell 8.38% to HK$37.4.

The sudden downturn follows a volatile session for the KOSPI index, which had surged more than 3% at the open before reversing course to trade down over 1%. Market participants point to multiple headwinds, including a fresh wave of selling in long-dated U.S. Treasuries, with the 30-year yield breaking above 5.3% for the first time since 2007.

Geopolitical tensions added further pressure, as the 60-day ceasefire memorandum of understanding between the U.S. and Iran expired on August 17 without extension. President Trump's explicit statement against renewing the agreement has pushed U.S.-Iran relations back into deadlock, triggering a sharp spike in crude prices. Brent futures climbed above $90 per barrel, intensifying risk-off sentiment across Asian markets and fueling the equity selloff.