Investing

Build a Simple Index Fund Portfolio in 2026 — 2026 US Guide

How to build a 3-fund index portfolio from scratch — the exact funds, allocation by age, rebalancing strategy, and where to open your account.

Kike Faúndez
Written by
Founder of CashControlly
Published on 9 min read
Investing9 min read

Jack Bogle's 3-fund portfolio is the most evidence-backed investment strategy available to individual investors. It beats 90%+ of actively managed funds over 20-year periods — and takes 30 minutes per year to maintain.

The 3-fund portfolio

  1. US total stock market: VTI (Vanguard) or FSKAX (Fidelity) or SWTSX (Schwab)
  2. International developed markets: VXUS (Vanguard) or FTIHX (Fidelity) or SWISX (Schwab)
  3. US bonds: BND (Vanguard) or FXNAX (Fidelity) or SCHZ (Schwab)

Suggested allocations by age

AgeUS stocksInternationalBonds
20s60%30%10%
30s55%25%20%
40s50%20%30%
50s40%20%40%
60+30%15%55%

Where to open the account

BrokerAccount minimumsFund expense ratios
Fidelity$00% (Zero funds)
Vanguard$0 (ETFs), $3,000 (mutual funds)0.03-0.04%
Schwab$00.03-0.06%
M1 Finance$1000.03-0.06%

The rebalancing schedule

Rebalance once per year (or when any allocation drifts 5%+ from target). January 1 or your birthday are common anchors. Rebalance by contributing new money to underweight categories first — avoids selling and triggering capital gains taxes.

The expense ratio effect over 30 years
On a $100,000 portfolio: 0.04% expense ratio (Fidelity index fund) vs 0.75% (average actively managed fund). Over 30 years at 7% returns: the index fund portfolio grows to $749,000. The active fund portfolio grows to $625,000. The 0.71% fee difference costs $124,000. Not a typo.
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About the author

Kike Faúndez
Kike Faúndez
Founder of CashControlly · Santiago, Chile

Enrique 'Kike' Faúndez is an Information Systems and Management Control Engineer from Universidad de Chile, with master’s degrees in Finance from Universidad de Chile and Industrial Engineering from Pontificia Universidad Católica de Chile. He has 15+ years of experience in regulated financial services across finance, operations, and digital product development. He founded CashControlly in Santiago, Chile, with the conviction that personal financial control should not be a privilege, but an accessible and well-designed tool.

Credentials
  • Master's in Finance, Universidad de Chile
  • Master's in Industrial Engineering, Pontificia Universidad Católica de Chile
  • Information Systems and Management Control Engineer, Universidad de Chile
  • AI and ITIL certifications
  • 15+ years in regulated financial services
Learn more about the founder

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