VOO vs VTI vs FZROX: Which ETF Should You Choose in 2026?

VOO vs VTI vs FZROX — the short answer:

• VOO (Vanguard S&P 500 ETF): 500 large-cap US companies, 0.03% expense ratio, the most popular ETF by assets
• VTI (Vanguard Total Stock Market ETF): ~3,800 US companies (large + mid + small cap), 0.03% expense ratio, broader diversification
• FZROX (Fidelity ZERO Total Market Index Fund): ~2,500 US companies, 0.00% expense ratio (zero fees), available only at Fidelity

For a long-term investor, all three produce nearly identical results. Choose VTI or FZROX for a three-fund portfolio (better total-market diversification); VOO is fine if that's what your 401(k) offers.

VOO vs VTI vs FZROX — at a glance

Here is how the three funds compare on the metrics that matter for a long-term investor.

Historical Returns — The Numbers

10-year annualized returns (approximate, through 2024):

• VOO: 13.1% per year
• VTI: 12.8% per year
• FZROX: 12.7% per year (launched 2018; pre-2018 extrapolated from index)

On $100,000 invested for 10 years:

• VOO at 13.1%: $342,594
• VTI at 12.8%: $333,877
• FZROX at 12.7%: $330,869

The difference between best (VOO) and worst (FZROX) over this window: $11,725 on $100,000 — largely due to large-cap dominance in the 2014–2024 bull market. Mega-cap technology stocks (Apple, Microsoft, NVIDIA, Alphabet) carry heavy weight in the S&P 500 index and drove exceptional returns during this period. Small and mid-cap companies, which are unique to VTI and FZROX, did not keep pace with the largest names.

Why VOO outperformed VTI (2014–2024)

The S&P 500 is dominated by mega-cap technology stocks. In 2014–2024, large-cap tech drove the entire market higher. Small and mid-cap stocks — which are unique to VTI and FZROX — underperformed relative to large caps during this specific window. This is a cycle, not a structural advantage. In 2000–2012, small-cap stocks significantly outperformed large-cap stocks over the full period. The decade you invest in determines which market cap segment leads.

The honest answer: the fund you'll get richer with depends on which market cap segment outperforms in your investment window. Since neither you nor any professional analyst reliably knows this in advance, total market (VTI or FZROX) is the preferred choice — you capture whichever segment wins rather than concentrating on one.

The Case for VTI Over VOO

VTI holds approximately 3,800 companies versus VOO's 500. The additional 3,300 companies are mid-cap (market capitalization $2B–$10B) and small-cap (under $2B). This broader coverage matters for three concrete reasons.

1. Historical small-cap premium: Over 90+ years of data, small-cap value stocks have returned approximately 2–3% more annually than large-cap stocks. The "small-cap premium" is documented extensively in academic finance, most notably in the Fama-French Three-Factor Model (1992). However, this premium has been inconsistent in recent decades — particularly during the 2010s when mega-cap tech dominated returns. The premium exists in the long historical record but cannot be reliably counted on in any given 10–15 year window.
2. Broader diversification: 3,800 companies provide genuine exposure to US economic growth including companies that are not yet large enough for the S&P 500. Amazon, Tesla, and Google all spent years as mid-cap or small-cap companies before their explosive growth phases. VTI captures these companies at earlier stages of their trajectory; VOO only adds them after they've already grown large enough to qualify for the index.
3. No profitability selection bias: The S&P 500 index requires a company to report four consecutive quarters of GAAP profitability before inclusion. This creates a slight quality tilt and delays inclusion of fast-growing companies that are reinvesting heavily (and therefore not yet profitable). VTI includes these companies from an earlier stage, capturing more of the growth curve.

Verdict: For a three-fund portfolio, use VTI. The broader diversification aligns with the total-market investment philosophy and avoids concentration in a single market cap tier. If your 401(k) only offers VOO or a generic S&P 500 fund, use it without hesitation — the long-run difference is small.

The Case for FZROX — Zero Expense Ratio

FZROX carries a 0.00% expense ratio. This is genuinely zero — Fidelity charges no management fee whatsoever. The company subsidizes it as a customer acquisition and retention tool, betting that investors who hold FZROX will keep the rest of their financial lives at Fidelity, generating revenue through other products and services.

What the 0% ER saves over time:

• VTI at 0.03% on $500,000: $150 per year
• FZROX at 0.00% on $500,000: $0 per year
• 30-year compound impact of $150 per year at 8% return: approximately $17,000

That is real money. But it is the only meaningful financial advantage FZROX holds over VTI. The disadvantages are structural:

• Fidelity-only: FZROX cannot be transferred in-kind to Vanguard, Schwab, or any other brokerage. If you ever want to move your account, you must sell FZROX first — which triggers a taxable capital gains event if held in a taxable brokerage account. VTI and VOO are exchange-traded and transfer freely to any DTCC-registered broker without selling.
• Proprietary index: FZROX tracks Fidelity's own internally constructed US total market index rather than the CRSP US Total Market Index (VTI) or Russell 3000. The construction is similar and the economic exposure is nearly identical, but the index is less transparent and receives less independent third-party scrutiny than CRSP or Russell indexes.
• Mutual fund, not ETF: FZROX is a mutual fund. It prices and trades once per day at the end-of-day net asset value, not intraday like an ETF. You cannot place limit orders, stop-loss orders, or trade it during market hours. In taxable accounts, mutual funds can also be slightly less tax-efficient than ETFs in certain circumstances (see the FAQ below for detail).

Verdict: Use FZROX if you are committed to Fidelity for the long term and your account is primarily a tax-advantaged IRA or 401(k), where the portability concern is minimized. For taxable brokerage accounts where you may eventually transfer to another firm, VTI's portability is worth more than the 0.03% annual savings.

VOO vs VTI vs SPY — The Most Common Confusion

SPY (SPDR S&P 500 ETF Trust) tracks the same S&P 500 index as VOO but charges 0.0945% — three times VOO's 0.03% expense ratio. SPY exists because it was the first US-listed ETF, launched in January 1993, and institutional investors, hedge funds, and options traders use it extensively due to its unmatched liquidity. SPY has the highest average daily trading volume of any ETF in the world, which makes it the preferred vehicle for short-term hedging and large block trades. For long-term individual investors, VOO strictly dominates SPY at identical index exposure. There is no reason for a buy-and-hold investor to choose SPY over VOO.

Which Fund for Which Account Type?

The Real Answer — It Doesn't Matter Much

The long-run performance difference between VOO, VTI, and FZROX is approximately 0.1–0.4% annually. Over 30 years, the gap on a $500,000 portfolio is $20,000–$60,000 — real money, but dwarfed by the impact of other variables in your financial outcome.

What actually moves the needle, in order of importance:

1. How much you contribute monthly — the most important variable by far. Contribution amount compounds just like investment returns.
2. How long you invest — time in the market beats market timing in every measured period longer than 15 years.
3. Whether you stay invested during bear markets — selling during a 30–50% drawdown and buying back late destroys returns far more than any fund fee ever could. A single panic-sell in 2009 or 2020 permanently impaired compounding for those who did it.
4. Your stock/bond allocation — determines your effective long-run return range and your ability to hold through volatility without selling.
5. Fund selection among these three — the decision you are optimizing right now, and the least impactful of the five.

Spending 30 minutes analyzing VOO vs VTI vs FZROX while contributing $200 per month instead of $400 per month is the wrong optimization. A person contributing $400 per month in VTI will accumulate substantially more than someone contributing $200 per month in VOO — even though VOO outperformed VTI over the 2014–2024 window. The magnitude of contributions dominates the fund selection decision. Increase contributions first. Optimize fund selection second.

Key Takeaways

• VOO (S&P 500, ~500 stocks), VTI (US total market, ~3,800 stocks), and FZROX (US total market, ~2,500 stocks, 0% ER) all track similar assets at near-identical cost — no single choice is dramatically better than the others for a long-term investor.
• 10-year annualized returns differ by only 0.1–0.4% — largely driven by mega-cap tech outperforming small-cap in 2014–2024, which is a cyclical outcome that does not repeat predictably in the next decade.
• For a three-fund portfolio: use VTI (any broker) or FZROX (Fidelity only) — total market funds are preferred over large-cap-only for genuine long-run diversification across market cap tiers.
• FZROX's 0% ER saves approximately $17,000 over 30 years on a $500,000 portfolio — real money, but secondary to contribution amount and time horizon. The portability limitation makes FZROX suboptimal for taxable brokerage accounts.
• Contribution amount and staying invested through downturns matter 5–10 times more than the specific fund selection among these three options. Choose one and keep investing.

Build Your Allocation With These Funds

Frequently Asked Questions

Is FZROX really free? What is the catch?

FZROX genuinely has a 0% expense ratio — no management fee is charged under any circumstance. Fidelity subsidizes it as a customer acquisition and retention tool: investors who hold FZROX tend to keep their full financial lives at Fidelity, generating revenue through other products and services. The real constraints are structural: FZROX is only available at Fidelity, tracks a proprietary index with less independent oversight than CRSP or Russell, and is a mutual fund rather than an ETF. If you plan to stay at Fidelity long-term and your account is a tax-advantaged IRA or 401(k), FZROX is an excellent choice. In a taxable brokerage account where you might eventually transfer assets to another firm, VTI is preferable — the 0.03% annual cost is worth the portability.

Should I choose VOO or VTI for long-term investing?

VTI for a three-fund portfolio; VOO if that is your 401(k)'s only low-cost option. VTI's broader coverage (3,800 stocks vs 500) captures small and mid-cap stocks that have historically provided a return premium over longer periods. VOO's recent outperformance (2014–2024) reflects mega-cap technology dominance — a cyclical outcome that does not repeat predictably. Since you cannot know which market cap segment will outperform in your specific investment window, total market (VTI) is the intellectually consistent choice. You capture whichever segment wins rather than betting on large-cap continuing to dominate.

Can I hold both VTI and VOO?

There is no reason to. VTI includes everything in VOO plus approximately 3,300 additional mid and small-cap companies. Holding both creates roughly 99% overlap — you are effectively holding VOO twice in different wrappers, adding complexity without diversification. If you currently hold both, consolidate into VTI. Similarly, avoid holding VTI together with a separate small-cap fund like VB (Vanguard Small-Cap ETF) — VTI already includes small-cap stocks proportional to their market weight. Adding VB creates an unintentional small-cap tilt beyond market weight.

What is FXAIX and how does it compare?

FXAIX (Fidelity 500 Index Fund) is Fidelity's S&P 500 mutual fund equivalent of VOO — 500 large-cap US stocks at a 0.015% expense ratio (even cheaper than VOO's 0.03%). For Fidelity users who specifically want S&P 500 exposure, FXAIX is the lowest-cost option available. However, for a three-fund portfolio at Fidelity, FZROX (total US market) + FZILX (international) + FXNAX (US bonds) is preferable to FXAIX because total market coverage is broader and better captures US economic growth across all company sizes.

Which ETF should I buy in a taxable brokerage account?

VTI. In a taxable account, tax efficiency is an additional consideration on top of expense ratio and coverage. ETFs are structurally more tax-efficient than mutual funds because they use an in-kind creation and redemption mechanism that rarely triggers capital gains distributions inside the fund. VTI has distributed zero capital gains for most of its history, meaning you only pay taxes when you choose to sell — not when the fund manager rebalances internally. FZROX, as a mutual fund, is slightly less tax-efficient in a taxable account: fund-level rebalancing can generate capital gains that are distributed to all shareholders, creating a tax bill even if you did not sell. The recommendation is clear: VTI in any taxable brokerage account, FZROX in a Fidelity IRA or 401(k) where tax efficiency is already handled by the account structure.

Now that you have chosen your US stock fund, the next step is setting the right allocation across US stocks, international, and bonds. See the three-fund portfolio guide for the full allocation framework, or use the ETF allocation by age guide for age-specific recommendations.