⚡ Promptolis Original · Money & Finance
📈 Boglehead Portfolio Starter — 3-Fund Setup
Simple 3-fund portfolio (US stocks + international stocks + bonds) beats 90%+ of active managers over 20+ years per SPIVA research.
Why this is epic
SPIVA research: 90%+ of active funds underperform index over 20+ year periods. Yet average investor chases active funds + underperforms index by 2-3% annually (Dalbar research).
Boglehead 3-fund portfolio (John Bogle, Vanguard founder) is research-backed simplicity: 60% US stocks + 30% international + 10% bonds. Adjust allocation by age/risk tolerance.
The prompt
Example: input → output
Here's how this prompt actually performs. Real input below, real output from Claude Opus 4.
<age>35</age> <account-type>Roth IRA (new)</account-type> <total-to-invest>$7000 lump sum + $500/month ongoing</total-to-invest> <risk-tolerance>Medium</risk-tolerance>
Recommended Allocation
- 70% US Total Stock Market
- 20% International Stock Market
- 10% Total Bond Market
At age 35 with medium risk tolerance, more equity-heavy (90% stocks) is appropriate. Classic 'age in bonds' (35% bonds at 35) is too conservative for modern longevity. 90/10 split reflects 30+ year investment horizon.
Specific Funds
Vanguard (lowest fees):
- VTSAX (US Total Stock) — 0.04% expense
- VTIAX (International Stock) — 0.11% expense
- VBTLX (Total Bond) — 0.05% expense
Fidelity equivalents (slightly cheaper):
- FZROX or FSKAX (US Total Stock) — 0.00%-0.015%
- FZILX or FTIHX (International) — 0.00%-0.06%
- FXNAX (Total Bond) — 0.025%
Fidelity ZERO funds (FZROX, FZILX) have 0% expense — unbeatable for index investing.
Setup Steps
1. Open Roth IRA at Fidelity or Vanguard (both free)
2. Fund with $7000 lump sum (2025 Roth IRA limit)
3. Set up automatic monthly $500 contribution (you have room — $500 × 12 = $6000; full use of 2026 limit)
4. Allocate initial $7000:
- FZROX / VTSAX: $4900 (70%)
- FZILX / VTIAX: $1400 (20%)
- FXNAX / VBTLX: $700 (10%)
5. Set up auto-invest for monthly $500: same 70/20/10 split
6. Bookmark quarterly review date (not monthly — don't over-monitor)
Rebalancing
Annually — typically January 1 of new year:
- Check current allocation percentages
- If any fund >5% off target, rebalance
- Sell over-weighted (typically US stocks after strong year); buy under-weighted (typically international or bonds)
- In Roth IRA, no tax implications for rebalancing — free to adjust
Alternative: add new monthly contributions disproportionately to under-weighted categories. Natural rebalancing without selling.
Common Mistakes
- Checking portfolio weekly/monthly. Don't. You'll see volatility + be tempted to react. Quarterly max.
- Stock picking on top. '3 funds plus a few individual stocks I believe in.' Usually underperforms. Trust the index.
- Selling during market downturns. Biggest wealth-destroyer. Market recovers; buying during downturns accelerates wealth.
- Keeping 'special' allocation (crypto, specific sector). Fine in small amounts (<5%) but don't let it dominate.
- Paying advisor 1%+ AUM for this. For index portfolio, 1% AUM = massive cost over 30 years. Robo-advisor or DIY.
Target-date fund alternative: if even 3-fund is too complex, target-date fund (Vanguard Target Retirement 2055 for 35-year-old) does similar automatically. Slightly higher fee but simpler. Still beats active management.
Common use cases
- First investment setup
- Moving from managed funds to index
- Roth IRA / 401k allocation choice
- Simplifying portfolio from 10+ funds
- Teaching investing to family members
Best AI model for this
Sonnet 4.5.
Pro tips
- Vanguard or Fidelity — both excellent, low fees.
- Expense ratio under 0.10% — Vanguard has below 0.05%.
- VTI / VTSAX = total US market. VXUS / VTIAX = total international. BND / VBTLX = total bonds.
- Asset allocation matters more than fund selection.
- Rebalance annually — buy low, sell high automatically.
Customization tips
- For 401k with limited fund options: find lowest-expense total-stock-market + international + bond in your specific plan. Approximate 3-fund.
- For taxable brokerage account: tax-efficient fund placement matters. US stocks + international stocks in taxable; bonds in tax-advantaged (lower-yielding = less tax drag).
- For married couples: consider total-household allocation across all accounts. Not each account balanced individually.
- For FIRE seekers: higher savings rate matters more than fund selection. 3-fund Boglehead + 50% savings rate > sophisticated portfolio + 15% savings.
- For income-investors: dividend-focused alternative exists but total-return-with-systematic-withdrawals actually produces similar results with more flexibility.
Variants
Default 3-Fund
Classic 60/30/10 setup
Age-Adjusted (younger)
More stocks, less bonds
Age-Adjusted (pre-retirement)
More bonds approaching retirement
Roth IRA Specific
Tax-advantaged specifics
Single-Fund Alternative
Target-date fund simpler still
Frequently asked questions
How do I use the Boglehead Portfolio Starter — 3-Fund Setup prompt?
Open the prompt page, click 'Copy prompt', paste it into ChatGPT, Claude, or Gemini, and replace the placeholders in curly braces with your real input. The prompt is also launchable directly in each model with one click.
Which AI model works best with Boglehead Portfolio Starter — 3-Fund Setup?
Sonnet 4.5.
Can I customize the Boglehead Portfolio Starter — 3-Fund Setup prompt for my use case?
Yes — every Promptolis Original is designed to be customized. Key levers: Vanguard or Fidelity — both excellent, low fees.; Expense ratio under 0.10% — Vanguard has below 0.05%.
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