The S&P 500 consists of 500 constituents or companies that issue a total of 505 stocks. The list of these companies is called the Constituent List. The top 10 largest constituents are listed on the official Standard & Poor's website under the Equities Indexes section, or by following this link. S&P does not currently provide the total list of 500 on the website.

Key Takeaways

  • A constituent is a member or component of a market index or average like the S&P 500.
  • Companies must meet certain requirement criteria, which are determined by the publishers of the index, before being added to an index.
  • The value of an index is based on mathematical formulas that consider the share prices of all constituents within the index.
  • Currently, you can only find the top 10 most-heavily-weighted S&P 500 constituents on Standard & Poor's website.

S&P 500 Inclusion Criteria

The S&P 500 is one of the most widely quoted American stock market indexes because it represents the largest publicly traded corporations in the U.S. The S&P 500 focuses on the U.S. market's large-cap sector and is also a float-weighted index, meaning company market capitalizations are adjusted by the number of shares available for public trading.

To be added to the S&P 500, a stock must meet a broad spectrum of criteria, including a total market capitalization of at least $5 billion. Additionally, the stock must be issued by a U.S. company, have four consecutive quarters of positive earnings, and also meet certain liquidity requirements. Companies may be removed from the S&P 500 if they deviate substantially from these standards.

$21.42 trillion

The total combined market cap of the 500 companies in the S&P 500 is $21.42 trillion as of March 31, 2020.

S&P 500 Calculation

The S&P 500 is a free-float market capitalization-weighted index. This means that the more valuable an individual company's stock becomes, the more it contributes to the S&P 500's overall return. It is not uncommon for three-quarters of the index's return to be linked to only 50 to 75 stocks.

Therefore, the addition or subtraction of smaller companies from the index most likely will not have a noticeable impact on the overall return of the index. However, the removal or addition of even just one of the largest stocks can have an impact.

S&P 500 components are weighted by free-float market capitalization. Larger companies affect the value of the index to a greater degree.

Top 25 Components by Market Cap

As of March 31, 2020, the following are the twenty-five largest S&P 500 index constituents by weight:

  1. Microsoft Corp (MSFT)
  2. Apple Inc. (AAPL)
  3. Inc (AMZN)
  4. Facebook Inc (FB)
  5. Berkshire Hathaway (BBRK.B)
  6. Alphabet Inc- A shares (GOOGL) and Alphabet Inc- C shares (GOOG)
  7. Johnson & Johnson (JNJ)
  8. JP Morgan Chase & Co (JPM)
  9. Visa Inc (V)
  10. Procter & Gamble Company (PG)
  11. Mastercard Incorporated (MA)
  12. Intel Corp. (INTC)
  13. UnitedHealth Group (UNH)
  14. Bank of America (BAC)
  15. AT&T Inc. (T)
  16. Home Depot (HD)
  17. Exxon Mobil (XOM)
  18. Walt Disney Company (DIS)
  19. Verizon Communications (VZ)
  20. Coca-Cola Company (KO
  21. Merck & Co. (MRK)
  22. Comcast Corp.- A shares (CMCSA)
  23. Chevron (CVX)
  24. PepsiCo (PEP)
  25. Pfizer, Inc. (PFE)

Notably, Google-parent Alphabet has two share classes, A and C.