The S&P 500 is one of the most comprehensive and widely used benchmarks in the world, consisting of 500 large-cap U.S. companies across multiple industries. It’s often favored by analysts and investors as a true representation of the overall U.S. stock market. However, it is not the index composed of just 30 companies — that would be the Dow Jones Industrial Average.The S&P 500 is market-cap-weighted, meaning companies with higher total market value have more influence on the index’s movements. It includes firms like Microsoft, Johnson & Johnson, and ExxonMobil. While broader than the Dow, it serves a different function: offering a diversified look at the U.S. economy, rather than a more concentrated view of 30 flagship companies. Recognizing these distinctions helps investors make informed decisions when tracking market performance.