How do I build a three-fund portfolio?
In one paragraph
Three funds: a U.S. total stock market index fund, an international stock index fund, and a U.S. bond index fund — the allocation between them depends on your time horizon and risk tolerance, not on market predictions.
What this actually means
The three-fund portfolio is the simplest evidence-based portfolio strategy in retail investing. It provides complete U.S. equity exposure, international diversification, and bond stability through three holdings, typically at very low cost.
The standard fund choices at Vanguard: VTSAX (Vanguard Total Stock Market Index), VTIAX (Vanguard Total International Stock Index), and VBTLX (Vanguard Total Bond Market Index). Fidelity and Schwab have comparable zero-expense-ratio equivalents. The specific tickers matter less than owning all three asset classes at minimal cost.
Allocation frameworks: - Rule of 110 (or 120): subtract your age from 110 (or 120) to get your stock percentage. A 30-year-old would hold 80% (or 90%) in stocks split between U.S. and international, with the remainder in bonds. More aggressive investors use the 120 version. - Target date funds: these do the three-fund allocation automatically and shift toward bonds as retirement approaches. They're a simpler one-fund version of the same concept. - U.S. vs. international split: common approaches range from 20% to 40% of the equity allocation in international funds, reflecting the fact that U.S. markets represent roughly 60% of global market capitalization.
JL Collins in The Simple Path to Wealth advocates a version even simpler than three funds — a single total-market index fund (VTSAX) for the wealth accumulation phase, adding a bond fund only as retirement approaches. His argument: international diversification is already partially embedded in the earnings of large U.S. multinationals.
The three-fund portfolio's real advantage is behavioral, not technical. With only three decisions to monitor, there's less opportunity for tinkering, overtrading, or chasing performance — the behaviors that most reliably destroy investor returns relative to simply holding.
