If you invest in single asset class indexfunds like the Vanguard Total US StockMarketindex or the Spartan International Index at Fidelity, you can easily compare the performance of your individual holdings to the marketindex they track.
Just two indexfunds like the Vanguard TotalStockMarket and Total International StockIndex provide effective, economical, tax efficient global equity diversification.
Mr. Bogle believes that a simple portfolio including only two funds, the Vanguard TotalStockMarketIndex Fund and Total Bond MarketIndex Fund would be sufficient for many investors.