| Rank | Company | Ticker | Sector | Weight % | Market Cap | P/E Ratio | YTD Return |
|---|---|---|---|---|---|---|---|
| 1 | NVIDIA Corp | NVDA | Technology | 7.08% | $4321B | 36.3 | -3.02% |
| 2 | Apple Inc. | AAPL | Technology | 6.19% | $3780B | 32.6 | -5.63% |
| 3 | Microsoft Corporation | MSFT | Technology | 4.97% | $3037B | 25.6 | -15.03% |
| 4 | Amazon.com Inc | AMZN | Consumer Cyclical | 3.75% | $2289B | 29.7 | -7.49% |
| 5 | Alphabet Inc. (Class A) | GOOGL | Communication Services | 3.06% | $3610B | 27.6 | -3.68% |
| 6 | Alphabet Inc. (Class C) | GOOG | Communication Services | 2.85% | $3610B | 27.6 | -3.84% |
| 7 | Meta Platforms Inc | META | Communication Services | 2.67% | $1631B | 27.4 | -1.88% |
| 8 | Broadcom Inc | AVGO | Technology | 2.57% | $1567B | 64.5 | -3.35% |
| 9 | Tesla, Inc. | TSLA | Consumer Cyclical | 2.44% | $1489B | 368.7 | -9.83% |
| 10 | Berkshire Hathaway | BRK.B | N/A | 1.76% | $1061B | 15.8 | -1.00% |
The top 10 stocks in the S&P 500 by weight currently include technology giants like Microsoft (MSFT), Apple (AAPL), NVIDIA (NVDA), Amazon (AMZN), and Alphabet (GOOGL). These companies account for a historically high percentage of the index's total market capitalization.
In 2026, the S&P 500 is highly concentrated, with the top 10 companies representing over 37% of the total index weight. This level of concentration is significantly higher than historical averages, driven by the massive growth of mega-cap technology companies.
The Information Technology sector dominates the S&P 500, often accounting for nearly a third of the index's weight. It is followed by Financials, Healthcare, and Consumer Discretionary.
The S&P 500 is a float-adjusted market capitalization-weighted index. A company's weight is determined by taking its float-adjusted market capitalization (total market value of outstanding shares available to the public) and dividing it by the total float-adjusted market capitalization of all 500 companies in the index.
High concentration means the index's performance is heavily dependent on a small number of stocks. While this can drive massive gains when those top companies perform well, it also exposes investors to significant concentration risk if those specific mega-cap stocks experience a downturn.
S&P 500 constituent weights and sector breakdowns are compiled from index tracking data as of March 2026. Market capitalization, P/E ratios, and YTD performance metrics are sourced dynamically. The S&P 500 is a float-adjusted market-cap weighted index, meaning weights fluctuate daily based on market prices and outstanding shares.
Westmount Fundamentals. "S&P 500 Top 10 Stocks by Weight 2026." westmountfundamentals.com/sp500-top-10-holdings-weight-2026, 2026.