Thematic Investing: Analysis of Performance and Rotation in Morningstar Indexes

Thematic investing has gained significant traction in the global financial market in recent years, with thematic funds emerging as a popular investment choice for those looking to capitalize on emerging trends such as artificial intelligence, aging demographics, and alternative energy. These funds offer investors the opportunity to diversify their portfolios and reduce the risk associated with individual stock investments by focusing on specific themes or trends.

According to data from Morningstar, global assets in thematic funds have more than doubled in the five years leading up to September 2025, surging from USD 269 billion to USD 779 billion. Despite this impressive growth, the performance of thematic funds has been volatile, with periods of strong outperformance often followed by sharp reversals. The Morningstar Thematic Indexes have been used to evaluate the absolute return performance of different themes, revealing a mixed performance landscape where no single theme consistently outshines the rest year after year.

One key takeaway from the analysis of thematic indexes is the limited persistence of excess returns, with leadership rotating frequently across different time horizons. This underscores the challenge of timing a specific theme and highlights the potential value of adopting a rotation-based investment strategy. The excess-return correlation matrix further illustrates the low cross-theme co-movement, indicating that each theme has unique return drivers and constituent exposures. Active share analysis reinforces this idea, showing that several theme pairs exhibit 100% active share, meaning there is no overlap in holdings between themes.

The significant heterogeneity in underlying exposures across thematic indexes suggests that a systematic rotation framework could effectively capture shifts in thematic leadership and optimize risk allocation. Momentum-based selection within a rotation strategy has been shown to enhance risk-adjusted performance and reduce drawdowns compared to static portfolios. However, this approach comes with the trade-off of higher turnover rates and potentially increased transaction costs.

In conclusion, thematic investing offers unique opportunities for investors to align their portfolios with long-term trends and innovations shaping the global economy. However, the dynamic nature of thematic performance underscores the importance of a diversified investment approach that accounts for the rotational nature of thematic leadership. By implementing a systematic, rules-based theme rotation strategy, investors can potentially capitalize on thematic trends while mitigating risk and volatility in their portfolios.