As AI- and semiconductor-related stocks have posted conspicuous surges since the start of 2026, Nishioka Shin (西岡 伸) of Nomura Securities used quantitative methods to analyse whether stocks outside the AI theme could also become market drivers. A factor analysis compared the contributions of high- and low-volatility stocks and identified potential laggards.
While sharp rises in AI- and semiconductor-related stocks have driven Japanese equities, this analysis examines from a quantitative perspective the extent to which the market has become concentrated in AI. Using TOPIX500 as the investment universe, it observes the divergence in performance between AI-themed stocks and other stocks through changes in skewness. The analysis indicates that skewness has risen since the first half of 2025 and remained at a high level in April 2026.
The factor analysis uses seven factors, including share-price momentum, historical beta, market capitalization, forecast earnings growth and value-related indicators. Using TOPIX500 as the investment universe, it classifies stocks into high- and low-volatility groups and compares the contribution of each factor. Multiple charts quantitatively show that the factor contributions of high- and low-volatility stocks lie behind the movements in the indicators.
As conditions for stocks that could follow the sharp rise in AI- and semiconductor-related stocks, the analysis finds that low B/P stocks were relatively strong in June on the value factor (B/P), suggesting that the group of low-B/P stocks may have room to rise as laggards. A chart showing the performance of a factor-led strategy is also included, proposing regular reviews of the factors and rebalancing of stock selection.