Template:Index returns common intro

The growing proliferation of indexes from index providers, along with a corresponding growing number of index funds and exchange-traded funds (ETFs), creates a number of issues for investors, since the index returns of the different providers result in a dispersion of both yearly and multi-period returns. Dispersion of returns is not as considerable an issue with total market indexes, but as we go into style and smaller size indexes, dispersion of return increases in magnitude. These return differences are mainly due to the differing methodologies index providers utilize in constructing their indexes. Different benchmarks cover varying ranges of stocks, have different selection criteria for growth versus value, and are even maintained and rebalanced differently.

Each index provider's suite of index funds occupies the highlighted segment of the index strategy box.