Three low-cost index funds cover roughly the entire investable world. US stocks (VTI), international stocks (VXUS), and bonds (BND). That is it. Here is how to size the mix and why the Bogleheads swear by it.
READING TIME: ~7 MIN
VTI for US total market, VXUS for international, BND for bonds. That is the entire investable world in three tickers at roughly 0.03 to 0.07 percent expense ratios. Size by age: stocks dominate when you are young, bonds grow in share as you approach retirement. Over 15 years, roughly 85 to 90 percent of actively managed funds underperform the index. The three-fund portfolio stops trying to beat the market and just owns it.
Total diversification with minimal overlap. ETFs for taxable accounts (tax-efficient, commission-free at most brokers). Mutual fund equivalents inside a 401(k) that uses Vanguard, Fidelity, or Schwab funds.
One-fund alternative: VT (Vanguard Total World Stock) captures VTI + VXUS in a single ticker at 0.07 percent. Paired with BND, that is a true two-fund portfolio. VT tax efficiency in taxable accounts is slightly lower than holding VTI and VXUS separately (loses the Foreign Tax Credit deduction in certain cases).
The classic heuristic: stock allocation equals 120 minus your age. At 30, that is 90 percent stocks, 10 percent bonds. At 60, 60/40. At 75, 45/55. The exact numbers are not sacred; the direction is.
The US/International split within equities runs from 70/30 to 60/40 (US overweight) for most US investors. Vanguard's recommendation is closer to 60/40, reflecting the actual market-cap weighting of world equity markets. See Asset Allocation for the mechanics.
The SPIVA Scorecard (S&P Dow Jones Indices) has tracked active fund performance for two decades. Over any rolling 15-year window, roughly 85 to 90 percent of actively managed US equity funds underperform their benchmark after fees [VERIFY spglobal.com]. The number is higher for small-cap and international categories. Active management is not a skill problem; it is a math problem. The market return minus fees is what the average active dollar earns, by definition.
A 1 percent annual fee compounds to a 28 percent haircut of the final portfolio over 40 years versus a 0.03 percent index fund [VERIFY standard compounding math]. That is a decade of retirement spending, paid to a manager who statistically underperforms. The three-fund portfolio eliminates that drag.
Bitcoin is not a replacement for the three-fund portfolio. It is an optional sleeve alongside it, financed from the "offensive" portion of the plan after foundation is in place. Most fee-only advisors suggest 1 to 5 percent for conservative allocations, 5 to 10 percent for moderate, up to 10 to 20 percent for high risk tolerance. Some Bitcoin-focused investors hold more; the right number is the one where a total loss would not derail the financial plan.
A common implementation: 85 percent three-fund portfolio (sized by age), 10 percent Bitcoin, 5 percent cash and alternatives. Treat the Bitcoin allocation as the highest-volatility, highest-potential-upside sleeve. Rebalance on a calendar or threshold basis, not in response to price drama.
Over time, the fast-growing assets drift above their target weight. Rebalancing means selling a portion of what went up to buy what lagged, restoring the target allocation. Do it once a year (calendar rebalancing) or when any asset drifts 5 percentage points from target (threshold rebalancing). Inside tax-advantaged accounts there is no tax cost. In taxable accounts, use new contributions to buy the lagging asset before selling anything. Full mechanics in Rebalancing.
Last updated 2026-04-14. Not financial advice. Do your own research.