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What is a Index? SPX, SPY, NDX, IXIC


An index in the stock market measures the performance of a portfolio of stocks. It is a statistical measure. It is used to track changes in the overall value of a specific group of stocks. You can invest in a stock market index by purchasing index funds, exchange-traded funds (ETFs), or mutual funds that track the performance of a particular stock market index, such as the S&P 500 or the NASDAQ. These types of investments provide exposure to a diversified portfolio of stocks, allowing you to participate in the overall performance of the stock market without having to select individual stocks. An index is not an investment product, but rather a benchmark against which the performance of index funds, ETFs, mutual funds, and individual stocks can be measured. The most popular stock market indices are the S&P 500, the Dow Jones Industrial Average (the Dow), and the NASDAQ. The Dow Jones Industrial Average (the Dow, the DJIA) The first index was the Dow Jones Industrial Average, published in 1896. Financial reporter Charles Dow added up the closing prices of 12 of the largest stocks at the time and divided the total by 12 to get the average. Today, the Dow consists of 30 of the largest and most successful publicly traded companies in the U.S. To be included in the DJIA, a company must meet the following criteria:

  1. Be headquartered in the U.S.

  2. Be a large, well-established, and financially stable company

  3. Have a minimum market capitalization


Have publicly traded equity securities

  1. Be actively traded on the stock exchange

The specific criteria for inclusion in the DJIA can change over time, as the index is periodically reviewed and adjusted to reflect changes in the market. The companies in the DJIA are selected by a committee at S&P Dow Jones Indices, which is responsible for maintaining the index. The DOW is a price-weighted index, meaning that the stocks with a higher price have a greater impact on the index’s performance. Some believe that its measurement is less representative of the overall market than the S&P 500 even though they often perform similarly to each other. The DOW is often used as a benchmark for the overall performance of the U.S. stock market and is widely followed by investors and market participants. S&P 500 The S&P 500 measures the performance of 500 of the largest publicly traded companies in the U.S. Due to its broader exposure, some believe that the S&P 500 is the best measurement of the U.S. stock market. The S&P 500 is weighted by market cap. Market cap is the number of a company’s outstanding shares multiplied by the price per share. So the companies with the largest total market value have the greatest impact on the average of the S&P 500. T


he S&P 500 is widely followed by investors, both retail and institutional, as a barometer of the overall health of the U.S. stock market. The index is calculated and maintained by S&P Dow Jones Indices, a division of S&P Global. To be included in the S&P 500 index, a stock must meet certain criteria set by Standard & Poor’s, the company that manages the index. These criteria include:

  1. Market Capitalization: The company must have a market capitalization of at least $8.2 billion at the time of the review for inclusion.

  2. Liquidity: The stock must be highly liquid, meaning that there must be a substantial amount of trading volume in the stock.

  3. Public Float: The company must have a public float of at least 50% of its outstanding shares.


Financial Stability: The company must have a track record of profitability, with positive earnings in the most recent quarter and positive earnings over the past year.

  1. Sectoral Representation: The company must be classified in a GICS (Global Industry Classification Standard) sector that is already represented in the S&P 500 index.

  2. Exchange Listing: The company must be listed on the NYSE or NASDAQ and have its primary listing in the United States.

These criteria ensure that the companies in the S&P 500 are established, financially stable, and widely held by the public, providing a broad representation of the U.S. equity market. NASDAQ Composite NASDAQ (National Association of Securities Dealers Automated Quotations) is an American stock exchange that operates as a dealer market and is the largest electronic stock market in the world. NASDAQ Composite is an index composed of the largest and most actively traded technology-related companies listed on the NASDAQ stock exchange. Some of these companies may also be included on the Dow, the S&P 500, or both. The NASDAQ index is weighted by market cap. It can be used as a benchmark to track the performance of technology stocks. It includes more than 2500 stocks.



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