Despite recognizing the S&P 500 is now a concentrated bet, governance boards are reluctant to change it as their primary benchmark. Deviating from the industry standard introduces significant career risk, as it can be perceived as an attempt to retroactively justify underperformance, creating institutional inertia.
Historically, investors sought active managers for outperformance (alpha). With the S&P 500 becoming a concentrated bet on a few tech stocks, leading Chief Investment Officers now justify using active management primarily as a way to achieve the broad-based diversification that the main index no longer provides.
Conventional wisdom blames high fees and a "paradox of skill" for active management's failure. However, fees are at historic lows and increased manager skill should theoretically reduce market volatility. The fact that managers are performing worse despite these tailwinds indicates a deeper, structural market shift is the true cause.
The S&P 500 is no longer a passive, diversified market index. Its market-cap weighting has created a concentrated, active-like bet on a few dominant tech companies. This concentration is the primary reason it consistently beats most diversified active managers, flipping the script on the passive vs. active debate.