The S&P 500 is a broad index intended to capture the performance of a wide swath of American business.

Yet, so far this year, just 10 companies are responsible for about 90% of earnings growth.

In this video, Fool columnist Morgan Housel and Austin Smith discuss how this skew came about, and what it means for investors. 

 

Austin Smith owns shares of Apple and American International Group. Fool contributor Morgan Housel has no positions in the stocks mentioned above. The Motley Fool owns shares of Apple, American International Group, and Bank of America and has the following options: long JAN 2014 $25.00 calls on American International Group. Motley Fool newsletter services recommend Apple, American International Group, and Goldman Sachs Group. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.