S&P 500

What It Is

The S&P 500 is a stock market index tracking 500 of the largest publicly traded companies in the United States.

Why It Matters

It is widely considered the best single gauge of U.S. stock market performance and a benchmark for trillions of dollars in assets.

How It Works

  • Includes large‑cap U.S. companies across all major sectors
  • Weighted by market capitalization
  • Adjusted periodically by an index committee

Key Components

  • 500 large‑cap companies
  • Sector diversification
  • Market‑cap weighting
  • Index committee oversight

Example

Companies like Apple, ExxonMobil, and Johnson & Johnson are part of the S&P 500.

Key Takeaways

  • The S&P 500 reflects the health of the U.S. economy.
  • It is the most widely tracked equity index in the world.
  • Performance influences global investment flows.