Thematic investing is maturing beyond identifying big ideas and creating products. The new phase uses data and AI to systematically measure and track individual companies' exposure to themes in real-time, enabling a more dynamic, data-driven investment strategy.

Due to the heavy weighting of a few large tech companies, the S&P 500 no longer represents a diversified view of the economy. It functions more like a thematic fund for large-cap growth, primarily driven by AI, semiconductors, and software, making it a poor benchmark for non-tech strategies.

Given the high probability of a crash wiping out individual companies, the smart play is to bet on the entire AI sector's long-term success. Avoid debt, ignore short-term volatility, and hold a diversified portfolio for 20+ years, a timeframe that has historically overcome even major depressions.

Market concentration risk has evolved. Historically, the top 10 most valuable companies were diversified across sectors like banking, mining, and retail. Today, they are almost all tied to the single theme of AI, creating a new, concentrated form of systemic risk for large funds and the market as a whole.

To overcome the cognitive bias against high-priced assets in exponential markets like AI, create a separate portfolio "sleeve." This mentally segregates it from traditional investments, allowing for a long-term, "this time is different" mindset without disrupting the core portfolio.

To identify companies benefiting from a theme like deregulation, modern ETFs employ AI to screen earnings call transcripts. This data-driven approach quantifies how often company executives mention the theme, providing a more objective filter for stock selection than relying on sector analysis alone.

Drawing a parallel to the early internet, where initial market-anointed winners like Ask Jeeves failed, the current AI boom presents a similar risk. A more prudent strategy is to invest in companies across various sectors that are effectively adopting AI to enhance productivity, as this is where widespread, long-term value will be created.

While venture capital often praises contrarian thinking, during moments of fundamental technological shift like the current AI boom, the most rational strategy is to be consensus. The market is so open and growing so fast that betting on the obvious winners is the right move.

Financial firms tend to create thematic ETFs (e.g., AI, Clean Energy) after a sector is already hot and asset prices are inflated. Investors buying into the theme often arrive just as a market correction is imminent, leading to poor returns.