The S&P 500 is a renowned benchmark for large-cap U.S. equities. The index measures 500 leading companies and covers approximately 80% of investable market capitalization in the U.S. equity market. As of year-end 2025, over USD 23.3 trillion was benchmarked to the S&P 500 alone, with indexed assets making up USD 15.7 trillion of this total. Exchange-traded products based on the S&P 500 have been cross-listed in markets around the globe, but what creates the international appetite for U.S. equities, particularly the S&P 500?
In this paper, we will:
- Compare the S&P 500 to the local equity benchmark in Brazil;
- Explore the significance of the S&P 500 in global equity markets; and
- Compare S&P 500 performance to that of active U.S. large-cap funds.
Comparison of the S&P 500 and the Local Brazil Index
The S&P 500 and the S&P Brazil LargeMidCap are widely recognized performance indicators for the U.S. and Brazilian equity markets, respectively. Both indices can serve as benchmarks for the domestic stock market and equity fund performance. However, they differ significantly due to the distinct economic landscapes and financial market developments they reflect.
The S&P 500 comprises 500 companies and represents around 80% of the market cap of the U.S. equity market, while the S&P Brazil LargeMidCap measures the performance of companies representing the top 85% of float-adjusted market capitalization (FMC) in Brazil. Both are free float, market cap-weighted indices, but they differ significantly in their levels of concentration and exposure to the global economy.
Compared with the S&P Brazil LargeMidCap, the S&P 500 is considerably more diversified in terms of constituent weights. As of June 30, 2026, the 10 largest S&P 500 members represented 37.9% of the index, and the largest, Nvidia Corp., had a weight of 7.5%. In contrast, the 10 largest stocks in the S&P Brazil LargeMidCap accounted for 65.7% of the index, while the two largest, Petrobras S.A. and Vale S.A., had weights of 13.3% and 11.2%, respectively (see Exhibit 1).
