The surge was driven by three reinforcing catalysts: an overnight Wall Street rally on Federal Reserve rate-cut hopes, a tech/AI stock rebound following strong US earnings, and aggressive dip-buying after recent market declines.
Weak US jobs data sent the probability of a Fed rate cut at the September meeting to 91.9%, up sharply from 63.1% a week earlier . This triggered a powerful US stock rebound: the S&P 500 posted its biggest rally since May, and the Nasdaq jumped 2.59%, setting a positive tone for Asian markets .
Both Japanese and Korean markets had fallen in preceding sessions, drawing bargain hunters . A wave of dip buying and optimism about interest-rate cuts helped the S&P 500 post its biggest rally since May .
Strong US tech earnings (Meta, Palantir, Lloyds) reignited AI enthusiasm, lifting semiconductor and AI-linked stocks across the region . The tech mood shift was broad and decisive .
Eased concerns over tax reform proposals and expectations of domestic rate relief supported sentiment. Foreign investors and institutions bought a net 291.9 billion KRW and 94.5 billion KRW respectively, while individual investors sold 471.8 billion KRW .
| Stock | Gain | Notes |
|---|---|---|
| SK Hynix | ~7% | AI memory chip leader, benefited directly from renewed AI demand |
| Samsung Electronics | >4% | Tech sector strength and corporate governance reforms driving foreign inflows |
| KOSDAQ-listed tech stocks | Also rallied | Followed the KOSPI lead with broad-based gains |
| Stock | Gain | Notes |
|---|---|---|
| SoftBank Group | 9–10% (some reports say 14%) | AI/ARM exposure; surged as one of the top drivers of the Nikkei |
| Kioxia | ~7% | NAND flash maker, rallied with the semiconductor upturn |
Market sentiment was bolstered by industry-wide technological progress, specifically the launch of High Bandwidth Flash standards and advanced QLC 3D NAND technology, which strengthened investor risk appetite in AI and memory supply chains .
The sharp rally on August 5, 2025, was primarily a tech-driven, Fed-rate-cut-fueled rebound where dip buyers piled into semiconductors and AI-exposed names after a period of weakness. South Korea's KOSPI led the region on strong foreign institutional buying, with the Nikkei following close behind.