“Should everyone index everything? The answer is resoundingly “no”. In fact, if everyone indexed, capital markets would cease to provide the relatively efficient security prices that make indexing an attractive strategy for some investors. All the research undertaken by active managers keeps prices closer to values, enabling indexed investors to catch a free ride without paying the costs.
Thus there is a fragile equilibrium in which some investors choose to index some or all of their money, while the rest continue to search for mispriced securities.
Should you index at least some of your portfolio? This is up to you. I only suggest that you consider the option. In the long run, this boring approach can give you more time for more interesting activities such as music, art, literature, sports, and so on. And it very well may leave you with more money as well.”
– William F. Sharpe