VFIAX vs FXAIX: Which S&P 500 Index Fund Is Better? (2026)
VFIAX (Vanguard 500 Index Fund Admiral Shares) and FXAIX (Fidelity 500 Index Fund) are two of the most popular mutual funds in existence — and they both track the exact same index. So how do you choose? This comparison breaks down every meaningful difference so you can make the right call for your portfolio.
VFIAX vs FXAIX: At a Glance
| Metric | VFIAX | FXAIX |
|---|---|---|
| Fund Family | Vanguard | Fidelity |
| Index Tracked | S&P 500 (same for both) | |
| Expense Ratio | 0.04% | 0.015% |
| Minimum Investment | $3,000 | $0 |
| Assets Under Management | $1.42T | $715B |
| Holdings | 500 large-cap U.S. stocks (same) | |
| 1-Year Return | 16.51% | 16.22% |
| 3-Year Annualized | 19.21% | 19.13% |
| 5-Year Annualized | 11.67% | 11.64% |
| ETF Equivalent | VOO (0.03%) | — |
*Returns are approximate and based on recent historical data. Past performance does not guarantee future results.
Overview: Two Funds, One Index
VFIAX and FXAIX are about as close to identical as two different funds can be. Both passively replicate the S&P 500 index — a market-cap-weighted index of the 500 largest publicly traded U.S. companies, covering roughly 80% of the total U.S. stock market by value.
The differences between these funds are almost entirely structural — expense ratio, minimum investment, and the brokerage they're associated with. Performance will always be nearly identical because both track the same benchmark.
Expense Ratio Comparison
FXAIX charges 0.015% per year (or $1.50 per $10,000 invested). VFIAX charges 0.04% per year ($4.00 per $10,000). On a $50,000 portfolio, you'd pay $7.50/year with FXAIX vs $20/year with VFIAX. That's a $12.50 annual difference — trivial in isolation, but it compounds meaningfully over decades.
Tax Efficiency
VFIAX has a tax advantage through Vanguard's patented ETF share class structure. VFIAX has distributed zero capital gains to shareholders since 2000. FXAIX is also highly tax-efficient but doesn't have the same structural mechanism.
VFIAX vs FXAIX: Which Is Right for You?
Choose VFIAX if you…
- ✅ Have a Vanguard brokerage account
- ✅ Have $3,000+ to invest initially
- ✅ Value Vanguard's long track record (since 1976)
- ✅ Invest in a taxable account and want maximum tax efficiency
Choose FXAIX if you…
- ✅ Have a Fidelity brokerage account
- ✅ Are investing with less than $3,000
- ✅ Want the absolute lowest expense ratio
- ✅ Want access to Fidelity's research tools and fractional shares
Bottom line: Choose based on your brokerage.
Frequently Asked Questions
What is the difference between VFIAX and FXAIX?
Both track the S&P 500 and hold the same 500 stocks. The main differences: FXAIX has a lower expense ratio (0.015% vs 0.04%), FXAIX has no minimum investment vs VFIAX's $3,000 minimum, and VFIAX has larger AUM ($1.42T vs $715B). Performance is nearly identical.
Which has better performance: VFIAX or FXAIX?
FXAIX marginally outperforms by ~0.02-0.03% annually — exactly equal to its lower expense ratio. Both track the S&P 500, so returns will always be nearly identical.
Is VFIAX or FXAIX better for beginners?
FXAIX is better for beginners because it has no minimum investment. VFIAX requires $3,000.
Should I switch from VFIAX to FXAIX (or vice versa)?
No. In a taxable account, switching would trigger capital gains taxes that would far exceed any fee savings. Stay with what you have.
What are the ETF alternatives to VFIAX and FXAIX?
VOO (Vanguard S&P 500 ETF, 0.03% ER) and IVV (iShares Core S&P 500 ETF, 0.03% ER) are popular ETF alternatives.
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