Key Takeaways
- The 3-fund portfolio (US total market / international / bonds) gives most investors everything they need: broad diversification, low cost, and minimal maintenance
- Fidelity's ZERO funds (FZROX, FZILX) now charge 0.00% - the lowest cost available, but they're only transferable in-kind to another Fidelity account
- Vanguard's ETF equivalents (VTI, VXUS, BND) charge 0.03-0.07% and can be held at any brokerage
- For retirement accounts where you'll stay at Fidelity, the ZERO funds are hard to beat on cost
- For taxable accounts, portable ETFs (VTI, VXUS) may be smarter - selling to transfer out triggers a taxable event
- The difference in cost between Fidelity ZERO and Vanguard ETFs on a $100,000 portfolio is about $30-$70/year - meaningful at scale, negligible when starting out
After a year of stock-picking and sector ETF trading that took more time than it was worth, I switched to a simple 3-fund index portfolio — and I haven’t looked back. The strategy is straightforward: hold one US total market fund, one international fund, and one bond fund. Rebalance quarterly. Done.
What’s changed since I first wrote about this is the fund landscape. When I originally published this post in 2013, Vanguard was the clear winner on cost. That’s no longer true. Fidelity launched zero-expense-ratio index funds in 2018, and the cost comparison across brokerages has shifted meaningfully.
Here’s where things stand in 2026.
Why the 3-Fund Portfolio Works
The idea behind a 3-fund portfolio is to own the whole market, not try to beat it. Research consistently shows that most actively managed funds underperform their benchmark index over a 10-year period, net of fees. Owning index funds removes the stock-picking risk and eliminates the fee drag that compounds against you over decades.
The three building blocks:
1. US Total Stock Market — covers large, mid, and small-cap US companies (~3,800+ stocks). More diversified than an S&P 500 fund, with historically slightly higher long-term returns due to small/mid-cap exposure.
2. International Stock Index — developed and emerging market exposure outside the US. Provides geographic diversification that the US fund doesn’t cover.
3. Bond Market Index — stabilizes the portfolio during equity downturns and reduces overall volatility. The appropriate allocation depends on your time horizon and risk tolerance.
A common starting allocation for someone in their 30s–40s: 60% US / 30% international / 10% bonds. More conservative investors or those closer to retirement shift more toward bonds.
2026 Fund Comparison: Vanguard vs Fidelity vs Schwab
This is where the post needed a full update. The cost picture has changed a lot since 2013.
US Total Stock Market Funds
| Fund | Ticker | Expense Ratio | Minimum | Portable? |
|---|---|---|---|---|
| Fidelity ZERO Total Market | FZROX | 0.00% | $0 | Fidelity only |
| Fidelity Total Market Index | FSKAX | 0.015% | $0 | Yes |
| Schwab Total Stock Market | SWTSX | 0.03% | $0 | Yes |
| Vanguard Total Stock Market ETF | VTI | 0.03% | $1 (fractional) | Yes |
| Vanguard Total Stock Market | VTSAX | 0.04% | $3,000 | Yes |
International Stock Funds
| Fund | Ticker | Expense Ratio | Minimum | Portable? |
|---|---|---|---|---|
| Fidelity ZERO International | FZILX | 0.00% | $0 | Fidelity only |
| Fidelity Total International | FTIHX | 0.06% | $0 | Yes |
| Vanguard Total International ETF | VXUS | 0.07% | $1 (fractional) | Yes |
| Vanguard Total International | VTIAX | 0.12% | $3,000 | Yes |
Bond Market Funds
| Fund | Ticker | Expense Ratio | Minimum | Portable? |
|---|---|---|---|---|
| Fidelity US Bond Index | FXNAX | 0.025% | $0 | Yes |
| Vanguard Total Bond Market ETF | BND | 0.03% | $1 (fractional) | Yes |
| Vanguard Total Bond Market | VBTLX | 0.05% | $3,000 | Yes |
The Big Change: Fidelity’s ZERO Funds
In 2013 I concluded that Vanguard’s VTSAX won on cost. That’s no longer accurate. Fidelity launched FZROX and FZILX in 2018 with a 0.00% expense ratio — the lowest cost available anywhere.
On a $100,000 portfolio, that saves you about $30–40/year versus Vanguard ETFs. Not life-changing at that size — but at $500,000 it’s $150–200/year, and it compounds over time.
The catch: FZROX and FZILX are proprietary to Fidelity. If you ever move your account to another brokerage, you’d have to sell them first — which in a taxable account triggers capital gains taxes. In a Roth IRA or 401k where you plan to stay at Fidelity long-term, that’s not a concern. In a taxable account, it’s something to think about before committing.
My approach: I use the Fidelity ZERO funds inside my IRA at Fidelity. For any taxable account, I’d use VTI and VXUS — they’re portable and still extremely cheap at 0.03–0.07%. Selling FZROX to transfer out triggers a taxable event, so it’s also worth reviewing capital gains tax rates before making any switch in a taxable account.
I’ll update this page if expense ratios change. Subscribe here to get notified.
Mutual Funds vs ETFs: The 2026 Answer Is Different
In 2013, I chose mutual funds over ETFs largely because ETFs were harder to automate — you had to buy whole shares through a brokerage, which made regular monthly contributions awkward. That’s no longer true.
Most brokers now offer fractional shares on ETFs, so you can invest $500/month in VTI the same way you’d auto-invest in VTSAX. Commission-free ETF trading is also now the standard at Fidelity, Schwab, and most other major brokerages.
The practical difference today is minimal. If you’re using Fidelity and want the ZERO funds, go with mutual funds. If you want portability or plan to hold in a non-Fidelity account, ETFs are slightly more flexible.
Rebalancing: Simpler Than It Sounds
The main maintenance task with a 3-fund portfolio is quarterly rebalancing — checking whether your actual allocation has drifted from your target, and buying/selling to bring it back.
With just three funds, this takes maybe 20 minutes. Compare the current balance in each fund against your target percentage. If US stocks have run up and now represent 70% instead of 60%, sell a bit and shift to international or bonds to rebalance. Some brokers (Fidelity, Vanguard, Schwab) have automatic rebalancing features that handle this for you.
The other maintenance task is reassessing your stock/bond split as you age. A common rule of thumb is to hold your age in bonds — a 40-year-old holds 40% bonds. That’s conservative by most modern standards, but the principle of gradually shifting toward bonds as retirement approaches is sound.
What I Actually Hold
For the record: I use a variation of this approach, weighted toward US equities given my time horizon. FZROX for the US portion in my IRA, VTI in any taxable accounts, and VXUS for international. I’ve reduced bond exposure compared to a decade ago and will shift back gradually as I get closer to retirement.
The specific percentages are less important than the consistency of contributing and not touching it when the market drops.
Looking Ahead: 2027
Expense ratios on broad index funds have been on a long-term downward trend — the competition between Fidelity, Vanguard, and Schwab has been genuinely good for investors. It’s possible Fidelity expands the ZERO fund lineup, or that Vanguard responds with further cuts. I’d expect the core VTSAX/VTI and FZROX landscape to remain stable, but I’ll update these tables if anything changes.
Related reading:
- 2026–2027 Roth IRA and Traditional IRA Contribution and Income Limits
- 2026–2027 401(k), 403(b) and TSP Contribution Limits
- The Power of Compounding: $1 Million Now or a Penny Doubled for 30 Days?
- Capital Gains Tax Rates: Short-Term vs Long-Term
- 2026–2027 HSA Contribution Limits and Tax Rules
