S&P 500 - Monthly
Chart Description
The S&P 500 Index is a widely followed U.S. stock market index that is used to represent U.S. stock market performance. Other widely followed stock market indices include the Dow Jones Industrial Average and the NASDAQ Composite. The S&P 500 is a much broader index than either of those, and thus does a better job of measuring overall U.S. stock market performance. The S&P 500 is a market capitalization weighted index of the 500 largest market cap stocks listed on U.S. stock exchanges. Market capitalization refers to the overall value of all of all of a company's outstanding shares of stock. Being a market capitalization weighted index means that a change in the price of a stock with a larger market cap has causes more change in the overall index value than a change in price of a stock with smaller market cap.
This chart shows the monthly index value (aka price) on a log scale to better illustrate the relative size of price changes. The data in this chart goes back in time further than most S&P 500 data sets and comes from economist Robert Shiller.
Relevant Links
mccormick-charts.com: DJIA - Monthly, NASDAQ - Monthly
Wikipedia: S&P 500 Index, Market Capitalization
Other Links: Robert Shiller's data
