To review, the market cap of a company is calculated by taking the current stock price and multiplying it by the company's outstanding shares. extĬompany Weighting in S & P = Total of all market caps Company market cap ĭetermining the weighting of each component of the S&P 500 begins with adding up the total market cap for the index by adding together the market cap of every company in the index. The S&P 500 uses a market-cap weighting method, giving a higher percentage allocation to companies with the largest market capitalizations. Weighting Formula and Calculation of the S&P 500

You can't directly invest in the S&P 500 because it's an index, but you can invest in one of the many funds that use it as a benchmark, tracking its composition and performance.

stocks, and even the entire equities market.

Because of its depth and diversity, the S&P 500 is widely considered one of the best gauges of large U.S.The S&P is a float-weighted index, meaning the market capitalizations of the companies in the index are adjusted by the number of shares available for public trading.The S&P 500 Index was launched in 1957 by the credit rating agency Standard and Poor's.

publicly traded companies, with a primary emphasis on market capitalization. The S&P 500 Index features 500 leading U.S.

S p 500 index fund