Why the S&P 500’s Top 8 Stocks Aren’t as Concentrated as They Appear

Core Insights - The S&P 500's top eight stocks account for 27% of its total market capitalization but only 20-22% of its total earnings, indicating a modest premium rather than a bubble [1][2][4] - The concentration narrative is misleading as these companies operate in diverse sectors with different growth drivers and competitive dynamics [12][19] Market Capitalization vs. Earnings - The gap between market capitalization and earnings suggests that the market is pricing these companies at a 20-25% premium relative to their actual profit contribution [2][4] - A truly dangerous concentration would involve a much larger disparity between market cap and earnings [4] Business Diversification of Top Stocks - The top eight stocks include companies from various sectors: - NVIDIA focuses on semiconductors and AI chips [5] - Microsoft spans enterprise cloud, productivity software, gaming, and AI [6] - Apple operates in consumer electronics and services [7] - Amazon is diversified across e-commerce, cloud computing, and entertainment [8] - Meta primarily generates revenue from digital advertising [9] - Broadcom specializes in semiconductors and infrastructure software [9] - Alphabet operates in search, video, cloud, and AI [10] - Tesla is involved in electric vehicles and energy solutions [11] Quality Premium Justified by Fundamentals - The median operating margins for the top ten stocks increased by approximately 7 percentage points from 2015 to 2025, compared to 4 percentage points for the rest of the S&P 500 [14] - The median return on capital for the top ten stocks rose from 18% to 73%, indicating strong competitive advantages [14] Earnings Growth Comparison - In Q3 2025, the top companies delivered 14.9% year-over-year earnings growth, while the remaining companies grew at 6.7%, highlighting their superior profitability [15] - Analysts project that the top companies will contribute 33% of total S&P 500 earnings growth in 2025, down from 52% in 2024, suggesting a potential broadening of market contributions [16] Concentration Risk - Concentration risk exists primarily due to mechanical factors related to passive indexing rather than fundamental issues [17] - Historical examples show that concentration in specific sectors has occurred in the past without leading to market failures [18] Conclusion on Market Dynamics - The current concentration in the S&P 500 reflects efficient capital allocation towards profitable and innovative businesses rather than irrational market behavior [19][20] - The diversity of sectors represented by the top eight stocks supports a narrative of quality and competitive advantage [20]