Research: 46 companies generated half of stock-market wealth from 1926 to 2025

A study covering 1926–2025 found that just 46 firms produced half of the stock market's total wealth creation, even as the typical stock lagged sharply. The research also reports the broad market created $91 trillion in wealth over the century, while a value-weighted portfolio turned $1 into $15,401 versus $25.34 for Treasurys. Experts quoted in the report say these results highlight why many investors prefer broad diversification over trying to identify future standout stocks.