KOSPI plunges as AI selloff and yen intervention rock Asian markets

Asian equity markets fell sharply on Monday as South Korea's KOSPI plunged more than 5%, giving back a large chunk of its record 18% surge from Friday, while Japan's Nikkei 225 dropped over 2% after Tokyo and Washington confirmed a historic joint currency intervention that sent the yen surging to three-month highs against the dollar.

KOSPI Collapse Led by Memory Chip Giants

The KOSPI fell to 6,257 points, losing 5.12% from the previous session, according to Trading Economics. Samsung Electronics dropped more than 7% to trade at 242,500 Korean won, while SK Hynix ↗ 5.53% fell 7.57% to 1.588 million Korean won. The two chipmakers, which together account for more than half of the KOSPI's market capitalization, have been at the center of a broader AI and semiconductor selloff that saw the benchmark plunge 22% in July — its steepest monthly decline since the 2008 financial crisis.investing+2

The selling was compounded by developments in the United States. Micron ↗ 6.25%, which had surged 18% the day before, plummeted 5.9% on August 1 after Apple ↗ 2.43% CEO Tim Cook suggested the company may seek DRAM procurement sources beyond the three dominant suppliers. "The DRAM market is primarily composed of three suppliers. Increasing the number of suppliers could help secure volume and may also be beneficial in terms of pricing," Cook said during Apple's July 30 conference call, according to the Chosun Ilbo. Kioxia bucked the trend, surging nearly 9% after announcing a share buyback program and stock split.chosun+1

Yen Intervention Hammers Japanese Exporters

Japan's Nikkei 225 fell 2.2% to 62,956.48 as the yen strengthened sharply following confirmation that Japan and the United States had jointly intervened in currency markets — the first coordinated action since 2011. Finance Minister Satsuki Katayama said the intervention targeted "excessive volatility and disorderly movements" after the yen hit 163.99 to the dollar on July 23, its weakest in about 40 years. The yen surged to 155.20 against the dollar, its strongest level in nearly three months.economictimes+3

Toyota Motor dropped 5.3% and Suzuki slumped around 8% as the stronger yen threatened to erode overseas earnings. SoftBank Group traded 1.2% higher, while Kioxia emerged as one of the session's biggest gainers.economictimes

China Resilient; Oil Falls on Iran Diplomacy

Chinese markets were comparatively steady. The Shanghai Composite lost 0.5%, while Hong Kong's Hang Seng edged 0.3% higher as Alibaba ↘ 3.72% surged more than 5% after unveiling a new AI model. Oil prices fell after President Donald Trump said negotiations over the Strait of Hormuz would begin Monday, raising hopes of a diplomatic breakthrough with Iran. Brent crude dropped 7.5% to $83.43, pressured by the geopolitical de-escalation alongside weak manufacturing data and OPEC+ signals of faster production-cut phase-outs.tradingkey+1