[Bubba_Leroy]

Keep in mind that an index is simply a list of stocks that someone has chosen to include in the list.

A large index like the S&P 500 has more stocks and covers a broader range of the market than a smaller index like the Dow Jones Industrials, but both indexes are simply lists of stocks that someone has picked.

[aMorePerfectUnion]

Bubba,
I realize what an index is. My points remain true.

[Alberta's Child]

Yes, but if there's an objective reason why the stocks are included on the list then the person who chooses to include these stocks on the list doesn't have much flexibility over what gets chosen.

The S&P 500, for example, is comprised of the 500 largest U.S. stocks, as measured by market capitalization. The companies in the list can change, but only as a result of changes in the size of the company (or in cases of mergers, such as Exxon-Mobil).