TradingKey - On September 30, Japanese and South Korean stock markets diverged, with Japanese stocks strengthening significantly while South Korean equities edged lower. The Nikkei 225 Index closed up 1.94% at 66,753.50, while the Korea Composite Stock Price Index (KOSPI) closed down 0.48% at 6,838.05.

Source: TradingView

South Korean tech stocks ended mixed, with SK Hynix closing up 0.62% at 1.776 million won (approximately $1,312), while Samsung Electronics fell 1.47% to 268,500 won. In the Japanese market, Kioxia closed up 1.20% at 18,095 yen (approximately $115), and SoftBank Group surged 6.55% to 6,430 yen.

In terms of quarterly performance, the South Korean stock market underwent a notable correction. Over the three months ended September 30, the KOSPI accumulated a decline of 18.8%, making it one of the world's worst-performing stock markets in the third quarter. The AI trades, once highly sought-after earlier in the year, faced concentrated unwinding at the start of the quarter, leaving semiconductor leaders such as Samsung Electronics and SK Hynix among the most affected stocks.

Samsung Electronics and SK Hynix were previously viewed as key targets for positioning in the AI supply chain, with their combined market capitalization accounting for roughly half of the total market cap of South Korean equities. Following the stock price adjustments, their forward price-to-earnings ratios have now fallen back to around the 4x to 5x range, reflecting a significant contraction in overall South Korean market valuations compared with earlier levels.

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