John Bogle on Investing: The First 50 Years provides a good insight into the mind of John Bogle, the founder of The Vanguard Group. The only  book I have read by Bogle, it explains in detail his belief that individual stock picking is not worth the effort.  Instead, Bogle argues that the variance of the return on a total market index decreases as an investor considers a longer time horizon. In other words, the fifteen year return will tend to converge toward the fifteen year average return. A more detailed explanation is provided in the book. This approach suggests that the best strategy would be to invest in a low expense fund that follows either the S&P 500, the Wilshire 5000, or some market index. (ISBN-13: 978-0071761031)