S&P Global owns the index business that publishes the widely followed S&P 500.
S&P Global is the parent company of S&P Dow Jones Indices, the joint venture responsible for the S&P 500 and many other financial benchmarks. The S&P 500 tracks 500 large U.S. companies and is widely used as a gauge of the U.S. stock market.
The index is not a list ranked simply by the largest 500 companies. It uses eligibility rules and a committee-based selection process, while its constituents are weighted largely by float-adjusted market capitalization. That means companies with greater publicly available market value have greater influence on index movements.
S&P Global also provides credit ratings, financial data, and commodity-price information. Its market capitalization reflects these information businesses, not ownership of the companies included in the S&P 500.