A three fund portfolio is a simple approach to investing that, as the name suggests, involves just three mutual funds or exchange-traded funds. In just three funds, an investor can build a diversified, low cost portfolio that's easy to manage.Popularized by the Bogleheads, the three fund portfolio is one of several "Lazy Portfolios."  You don't let the Simplicity fool you. A three fund portfolio has outperformed most comparable actively managed portfolios Over the past several decades. In this article, we'll look at what comprises a 3-fund portfolio, its diversification, its historical returns, and how to easily build a 3-fund portfolio. We'll also look at a few ways you can supercharge the returns with a significant increase to volatility by adding a few more funds to the mix.