Japan and South Korea Close Mixed, SoftBank Retraces Gains, Samsung Share Price Hits New High

TradingKey - Japanese and South Korean stock markets ended mixed on Tuesday. The Nikkei 225 Index closed down 0.30% at 66,734.02 points. The KOSPI Index closed up 0.15% at 8,801.49 points.

[Source: TradingView]

The Nikkei 225 Index plunged more than 1,100 points intraday, falling below the psychological 66,000-point mark. AI and semiconductor-related stocks faced significant profit-taking, dragging the index lower.

In terms of individual stocks, SoftBank Group surged over 4.5% in early trading, primarily driven by investor pursuit following the news that Arm ( ARM) had soared in overnight trading, with its closing gain narrowing to 1.07%.

Notably, in the previous trading session, SoftBank Group's share price jumped 14.71%, bringing its market capitalization to approximately 49 trillion yen and surpassing Toyota Motor to become the most valuable company on the Tokyo Stock Exchange. Analysts noted that SoftBank's plan to invest approximately 75 billion euros in AI infrastructure in France continues to bolster investor confidence.

[Source: TradingView]

In South Korea, the KOSPI Index experienced extreme intraday volatility, dropping from above 8,900 points to around 8,500 points within the first five minutes of the opening and falling over 3.3% at one point. Performance among heavyweight stocks diverged: memory chip leader SK Hynix closed down 0.13%, while Samsung Electronics rose more than 6% intraday to hit a record high, closing at 330,500 won, up 3.3%.

Overall, while the recent AI wave continues—with U.S. chip giant Nvidia ( NVDA) rising over 6% on Monday after releasing a new AI processor—risk-off sentiment triggered by recurring geopolitical tensions in the Middle East, coupled with a concentrated wave of profit-taking, has exposed Japanese and South Korean markets to significant short-term volatility risks.