Nvidia, Apple, Microsoft Now Dominate 21% of S&P 500

The S&P 500 has reached a new level of concentration, with Nvidia (NASDAQ: NVDA), Apple (NASDAQ: AAPL), and Microsoft (NASDAQ: MSFT) now making up over 21% of the index. This marks a record high for combined weighting, surpassing even the peak influence of IBM (NYSE: IBM), AT&T, and ExxonMobil in the mid-1980s, which collectively accounted for 13.4%.

The rise in concentration has been driven by recent corporate developments that boosted share prices for all three companies. Nvidia recently announced a $150 billion stock buyback plan, the largest in history, bringing its total buyback authorization to $235 billion. The move reflects strong confidence in the company’s financial future and its leading position in AI chip design.

Apple’s stock has also surged, nearing record highs after its mid-September product event. The event introduced the iPhone Duo, a folding device with expandable screens, along with the new iPhone 18 suite and updated AirPods, setting the stage for a strong holiday season.

Microsoft’s stock has advanced as well, though without major announcements. Analysts have raised earnings estimates, citing expectations of strong Azure cloud sales growth driven by surging AI demand. The concentration of these three tech giants highlights how the broader market’s performance is increasingly tied to their success.