These 3 Powerhouse Stocks Drive 17.2% of the S&P 500's Gains
The S 500 (SNPINDEX: ^GSPC) market index is weighted by market cap. Companies with larger total market values contribute more to the index score.
As a result, the largest American stocks carry the most weight among the S&P 500's members. You probably know all about the top three names, whose weighting adds up to 17.2% of the leading market index's score:
Source Fool.com