Market analysis: The recent sharp rise in the Nikkei Index is highly concentrated in a few stocks, with a trend similar to the Korean stock market. A short-term pullback is expected.

The current surge is highly concentrated in a few sectors, mainly led by artificial intelligence-related stocks, while the market's sustainability appears relatively weak. According to media estimates, since April, over 80% of the gains in the Nikkei Average have come from the top ten weight contributor stocks, such as SoftBank Group and Advantest—significantly higher than the over 30% share seen in February when the index reached a stage high this year. In October last year, driven by the so-called “Takaichi rally” after Sanae Takaichi was elected Prime Minister, combined with the rise of technology stocks, these leading stocks contributed nearly 90% of the gains. However, after the Nikkei Index peaked at the end of that month, it fell by nearly 7% in about three weeks.