South Korea's Kospi swung from an early 2.15% gain to a 1.55% loss on Tuesday, closing at 6,869.83 after long-dated U.S. Treasury yields climbed to multi-decade highs and renewed Middle East tensions lifted oil prices. The intraday range reached 427.84 points, the widest since early August, while the tech-heavy Kosdaq dropped 3.52% to 834.20. Foreign investors extended their net buying streak on the Kospi board to five sessions, purchasing a net 86.1 billion won, and the won strengthened to 1,411.8 per dollar, but those supportive signals were outweighed by institutional selling of more than 780 billion won and pressure on semiconductor names including Samsung Electronics, SK Square and Samsung Electro-Mechanics. Analysts cited tighter liquidity as 30-year U.S. Treasury yields rose above 5.32% and 10-year yields topped 4.72%, with attention now turning to Nvidia's earnings and the Federal Reserve's Jackson Hole symposium as the next key tests for semiconductor sentiment and global rate expectations.