Zero Fee, Non-Zero Benchmark Risk: Why Fidelity's ZERO Funds Optimize the Wrong Variable

Zero Fee Does Not Mean Zero Tradeoffs

Fidelity's ZERO funds (FZROX, FZILX, FNILX) are among the most recommended funds on Reddit and YouTube. The pitch is simple: they charge 0.00% in expense ratios. Why pay Vanguard 0.03% for VTI when you can get "the same thing" for free?

The funds are fine. They are not scams, they are not traps, and they are perfectly reasonable holdings for many investors. But the "0.00% expense ratio" marketing optimizes the wrong variable. It draws attention to the least important basis points while quietly accepting proprietary benchmark risk, narrower market coverage, and non-trivial deviations from the broad-market exposure most investors think they are buying.

The right question is “How closely do I capture the market I actually want to own?” Fees matter, but they are a tiebreaker once benchmark fit is settled.

The Benchmark Problem

The ZERO funds do not track the same benchmarks as VTI, VXUS, or the S&P 500. They track Fidelity's own proprietary indices. Those indices are narrower.

Holdings data from Fidelity Fund Research and Vanguard (March 31, 2026). FZROX tracks Fidelity's U.S. Total Investable Market Index (top ~3,000 companies). VTI/VTSAX tracks CRSP US Total Market (~100% of investable U.S. market including micro-caps).

The international gap is the most striking. FZILX holds 2,179 stocks. VXUS holds 8,862. Fidelity's index selects the top 90% of stocks by market cap within each country, excluding small caps that VXUS includes. For "total international," FZILX is a meaningfully different and narrower portfolio.

The Fee Savings Are Tiny

FZROX charges 0.00%. VTI charges 0.03%. On a $100,000 portfolio, that is a $30/year difference. Over 25 years with contributions, the fee savings amount to a few hundred dollars. That is real money, but it is not the most important variable.

Meanwhile, the benchmark-related return dispersion between FZROX and VTI has historically been 10-50+ basis points per year in either direction. A 10 basis point annual return gap on the same $100,000 portfolio compounds to thousands of dollars over 25 years. The fee savings are 3 basis points. The benchmark risk is 10-50 basis points. The benchmark choice matters 3-15 times more than the fee.

See It For Yourself

The calculator below shows how a tiny fee difference compares to a modest benchmark return gap over time. Adjust the "benchmark dispersion" slider to see how quickly even a small return difference dominates the fee savings.

Recent Performance: The Nuanced Picture

Over the 5 years ending March 31, 2026:

This is the uncomfortable nuance: some ZERO funds have recently outperformed their canonical alternatives, while others have underperformed. The dispersion in both directions is far larger than the 3 basis point fee savings. That is exactly the point:the benchmark choice drives the outcome, not the fee.

What You Are Actually Giving Up

• Benchmark transparency. VTI tracks the CRSP US Total Market Index, maintained by the University of Chicago's Center for Research in Security Prices. FZROX tracks Fidelity's proprietary U.S. Total Investable Market Index. One benchmark is maintained by an independent academic institution. The other is maintained by the fund company itself.
• Market completeness. FZROX covers ~2,500 stocks (top ~3,000 companies). VTI covers ~3,500+ including micro-caps. FZILX covers ~2,200 international stocks. VXUS covers ~8,800. The ZERO funds are less complete proxies for the investable market.
• Portability. ZERO funds are only available in Fidelity brokerage accounts. If you move to Schwab, Vanguard, or another broker, you must sell and rebuy, potentially triggering capital gains. VTI/VXUS are ETFs that transfer to any brokerage.

When ZERO Funds Make Sense

• You are already at Fidelity and plan to stay. The portability issue does not apply.
• You are investing small amounts. On a $5,000 portfolio, 3 basis points is $1.50/year. The fee difference is truly negligible and the ZERO funds' no-minimum requirement is a genuine advantage.
• You understand the benchmark tradeoff and accept that you are buying a narrower market proxy in exchange for zero fees.

When They Do Not

• You want the broadest possible market capture. VTI, VXUS, and VT give you more complete market coverage.
• You may switch brokerages. ZERO funds must be sold; VTI/VXUS transfer in-kind.
• You believe "0.00% fee" means "best possible fund." The fee is one variable among many. Benchmark design, holdings breadth, and index governance matter more when fees are already tiny.

The Right Framework

For a core index fund, the goal is not "lowest fee." The goal is beta as close as possible to the intended market portfolio, with as little avoidable net drag as possible. That means evaluating two layers:

1. Benchmark choice risk: What market are you actually indexing? How complete is the coverage? Who maintains the rules?
2. Implementation drag: Fees, trading costs, cash drag, securities lending revenue, taxes, and sampling.

ZERO-fee marketing focuses almost entirely on layer 2 while downplaying layer 1. For most investors, layer 1 matters more once fees drop below 5 basis points.

As Robertson's research shows, index investing is delegated management to the index creator. The ZERO funds delegate to Fidelity's proprietary index team. VTI delegates to CRSP. Both are active choices. See the Passive Investing guide for the full framework.

Frequently Asked Questions

Are Fidelity ZERO funds bad?

No. They are fine investments. The critique is not that they are bad funds but that "0.00% expense ratio" is the wrong reason to choose them. Benchmark design, holdings breadth, and portability are more important variables when fees are already tiny.

Is FZROX the same as VTI?

No. FZROX tracks Fidelity's proprietary U.S. Total Investable Market Index (~2,512 holdings). VTI tracks the CRSP US Total Market Index (~3,520 holdings including micro-caps). They have similar but not identical exposures.

How much do I actually save with zero fees vs. 0.03%?

On a $100,000 portfolio: $30/year. On $500,000: $150/year. Over 25 years with contributions, the total fee savings are a few hundred to a few thousand dollars. Meanwhile, benchmark-related return dispersion can be 10-50+ basis points per year, which compounds to far larger dollar differences.

Can I transfer ZERO funds to another brokerage?

No. ZERO funds are proprietary to Fidelity and cannot be held at other brokerages. If you switch, you must sell (potentially triggering capital gains) and rebuy equivalent funds. ETFs like VTI and VXUS transfer in-kind to any brokerage.

Do ZERO funds underperform VTI?

Not always. Over the 5 years ending March 2026, FZROX outperformed VTSAX by 0.26% annually while FNILX underperformed FXAIX by 0.23%. The dispersion goes both directions, which is exactly the point: benchmark choice, not fees, drives the outcome.

Key Takeaways

• Fidelity ZERO funds are fine investments. There is no evidence they are categorically better or worse than VTI, VXUS, or their Fidelity non-ZERO counterparts.
• The fee savings are 3 basis points. On most portfolios, that is tens of dollars per year. Benchmark design risk is 10-50+ basis points. The benchmark matters 3-15x more than the fee.
• ZERO funds track narrower proprietary benchmarks. FZROX has 2,512 holdings vs. VTI's 3,520. FZILX has 2,179 vs. VXUS's 8,862. Less complete market coverage.
• Portability is a real cost. ZERO funds cannot transfer to other brokerages. ETFs can.
• The right question is not "What's the fee?" It is "How closely do I capture the market I actually want to own?"

Related Guides

• The S&P 500 Is Passive for You, But Not Under the Hood covers how benchmark design and committee governance shape what an index fund actually owns.
• Passive Investing Is a Label covers the broader framework on where discretion lives in index investing.
• The Case for Global Diversification covers why FZILX’s narrower international coverage matters.
• The Tech Bro Portfolio is another case where fund selection decisions matter more than investors think.
• Dividends Are Not Free Money is another common misconception about what drives returns.