This is unprecedented. Micron, $MU, and Nvidia, $NVDA are expected to account for 36% of the S&P 500’s earnings growth in Q3 2026 earnings season. This comes as $MU and $NVDA are expected to contribute +5.2 and +4.6 percentage points to the index’s +27% YoY earnings growth, respectively. Meanwhile, the next 8 top contributors are projected to add +8.2 percentage points, accounting for ~30% of the estimated S&P 500’s net income growth. Then, the remaining 490 stocks are set to contribute just +9.2 percentage points, representing 34% of the index’s projected earnings growth. Excluding those top 10 contributors, earnings growth is estimated to decline -11% YoY in Q3. Never in history have we witnessed market concentration like this.