Japanese stock market review (June 2026)

Research evidence excerpt

Japanese stock market review (June 2026)

2 July 2026

Mizuho Securities Equity Research Strategy / Equity

Japan Equity Strategy

Bullish sentiment prevails, but some concerns about bad news beginning to emerge

Global Senior Strategist: Daily price fluctuations actually becoming more volatile

Takaaki Hironaka In June, the Nikkei 225 rose 5.6% (3,732pt) MoM, while TOPIX edged up 0.9%

+81 3 6202 8554 (37pt). The Nikkei 225 and TOPIX both rose for the third straight month.

takaaki.hironaka@mizuho-sc.com

The stock market posted strong gains in April and May, so it comes as no

surprise that performance in June was somewhat subdued compared to the

previous months. However, when calculating the standard deviation of the

Nikkei 225’s daily percentage change, the figures show that volatility actually

increased—from 1.94 in April and 1.89 in May to 2.37 in June—making it a

month marked by significant swings in both directions. That said, in the Middle

East—which has been a source of global instability for over three months—

peace talks are moving forward, and there have been some positive signs,

such as a decline in crude oil prices.

AI-related stocks, which could be described as the core of the current market,

continue to deliver impeccable performance, demonstrating robust growth just

as they have in the past. At the same time, issues such as trends in data center

construction and free cash flow at hyperscalers are now being discussed.

In other words, it could be said that, with positive factors lacking novelty,

there was a noticeable tendency to focus on negative developments that were

somewhat newer. Against this backdrop, the fact that prices continued to rise

throughout the month indicates that market participants who are optimistic