AI Stocks Drive Vast Majority of S&P 500 Gains in 2026
The S&P 500 has added over $5 trillion in market cap this year, but nearly all gains come from just 84 AI-related firms and 22 energy stocks, while other sectors lost $1 trillion. AI now represents 47% of the index's market cap.
A new analysis shows extreme market concentration in 2026. The S&P 500 has gained more than $5 trillion in market capitalization so far this year, but the gains are almost entirely driven by two sectors: AI and energy.
AI stocks alone added $6 trillion in value, while the energy sector contributed $200 billion. Meanwhile, all other sectors combined erased $1 trillion from their market caps.
In practice, just 84 AI-related companies and 22 energy stocks account for the bulk of the index's advance. AI-related stocks now make up roughly 47% of the S&P 500's total market cap, near an all-time high and up from 27% in early 2023.
The data underscores how narrowly focused the market rally has become, with AI dominating investor attention and capital flows.
Source: The Kobeissi Letter