A mutual fund that charges you nothing to own it sounds like a marketing gimmick. But Fidelity's ZERO funds have carried a true 0.00% expense ratio since 2018, and as of July 2026 they remain the only major index funds in the country with no fee at all.
This guide covers the full range of Fidelity index funds: the ZERO lineup, the nearly-free core funds, the one real catch, and how they stack up against Vanguard and Schwab.
What Are Fidelity Index Funds?
Fidelity index funds are mutual funds that track a market index instead of paying managers to pick stocks. You buy them in dollar amounts, they price once per day, and you can automate purchases on a schedule.
Fidelity's signature move is removing barriers: none of its index mutual funds require a minimum investment, so you can start with $1 in a regular brokerage account or an IRA.
Fidelity ZERO Index Funds Explained
The ZERO funds are four index funds with a 0.00% expense ratio, no minimums, and no hidden loads. As of July 2026:
| Ticker | Fund | What it tracks | Expense ratio |
|---|---|---|---|
| FZROX | Fidelity ZERO Total Market Index Fund | The entire U.S. stock market | 0.00% |
| FNILX | Fidelity ZERO Large Cap Index Fund | Large U.S. companies, similar to the S&P 500 | 0.00% |
| FZILX | Fidelity ZERO International Index Fund | International stocks | 0.00% |
| FZIPX | Fidelity ZERO Extended Market Index Fund | Small and mid-size U.S. companies | 0.00% |
How can they be free? The ZERO funds track Fidelity's own in-house indexes instead of licensing the S&P 500 name, and Fidelity treats them as a way to bring in customers who will use other services. You genuinely pay no expense ratio.
The Catch With ZERO Funds
There is one real trade-off: Fidelity ZERO funds cannot be transferred to another brokerage. They only exist at Fidelity. If you ever move your account, you must sell the funds first, and in a taxable account that sale can trigger capital gains taxes.
Inside a Fidelity IRA this barely matters, since selling inside an IRA has no immediate tax consequence. In a taxable brokerage account, think of ZERO funds as a long-term commitment to Fidelity. Also note that FNILX tracks a Fidelity large-cap index that behaves much like the S&P 500 but is not the official index.
Core Fidelity Index Funds Beyond ZERO
If you want funds that track the official indexes and travel between brokerages, Fidelity's core index funds cost almost nothing anyway. As of July 2026:
| Ticker | Fund | What it tracks | Expense ratio |
|---|---|---|---|
| FXAIX | Fidelity 500 Index Fund | The S&P 500 | 0.015% |
| FSKAX | Fidelity Total Market Index Fund | The entire U.S. stock market | 0.015% |
| FTIHX | Fidelity Total International Index Fund | International stocks, including emerging markets | 0.06% |
| FXNAX | Fidelity U.S. Bond Index Fund | The broad U.S. bond market | 0.025% |
FXAIX at 0.015% costs $1.50 per year on a $10,000 balance. The difference between that and a ZERO fund is 15 cents a month, so choose based on portability and index preference, not the fee.
How Fidelity Index Funds Compare With Vanguard and Schwab
Fidelity wins on minimums and headline price. Every Fidelity index fund starts at $0, while Vanguard's Admiral shares like VTSAX and VFIAX require $3,000 each. On cost, FXAIX (0.015%) edges Schwab's SWPPX (0.02%) and Vanguard's VFIAX (0.04%) as of July 2026.
In practice, all three families are so cheap that fees should not drive your decision. The bigger questions are where your other accounts live, whether you want ZERO-style lock-in, and which platform you find easiest to use.
How to Buy Fidelity Index Funds
Getting started takes a few minutes:
- Open a Fidelity brokerage account, Roth IRA, or traditional IRA.
- Link your bank and transfer any amount, even $10.
- Search the ticker, like FZROX or FXAIX, and enter a dollar amount.
- Set up recurring investments so the plan runs itself.
Prefer an app-first experience or want ETFs instead of mutual funds? Robinhood offers commission-free fractional investing in thousands of ETFs starting at $1, with recurring buys and an IRA that includes a match on eligible contributions, terms apply. Our Robinhood review walks through the details.
Robinhood
Robinhood
Robinhood is a trading platform that brings stocks, ETFs, options, futures, prediction markets, crypto, and retirement accounts together in one app.
Standout feature
One platform for stocks, ETFs, options, futures, prediction markets, and crypto
Fees
$0 commission on stocks, ETFs, and options.
Pros
Zero-commission trading on stocks, ETFs, and options
Cons
Best perks (high APY, lower margin rates) require Gold subscription ($5/month)
Public is another commission-free option with fractional shares, and it adds bond investing and a high-yield cash account alongside your portfolio. See our Public review for how it compares.
Public
Public
Investing for those who take it seriously. Invest in stocks, bonds, options, crypto & more.
Standout feature
A 5%+ yield Bond Account paired with 3.3% APY on cash — Public is one of the only consumer apps where idle and conservative money is treated as seriously as the equity portfolio.
Fees
Free
Pros
• Invest in stocks, bonds, crypto & more• Earn 3.3% APY* on your cash with no fees• 1% match when you transfer your portfolio• Lock in a 5%+ yield with a Bond Account
Cons
Customer support is in-app and email only, no phone
Whichever platform you pick, keeping contributions consistent matters more than the last 0.01% of fees. Monarch Money connects your 401(k), IRA, and brokerage accounts in one dashboard, so you can watch your net worth grow and catch any month where contributions slipped. Our Monarch Money review covers pricing and features.
Monarch Money
Monarch Money
Monarch Money simplifies personal finance by uniting all your accounts in one place—secure, ad-free, and built for couples. 50% off your first year when you sign up via Firstcard!
Standout feature
#1 rated budgeting app (WSJ). 50% off first year via Firstcard.
Fees
$14.99/mo or $99.99/yr ($8.33/mo)
Pros
Beautiful, ad-free interface (4.9★ App Store). Best budgeting app for couples and families. Comprehensive account syncing and cash flow forecasting.
Cons
No free tier — requires paid subscription.
This article is educational, not personalized investment advice. All investing involves risk, including possible loss of principal, and past performance does not guarantee future results.
Frequently Asked Questions
Is FZROX really free?
Yes. FZROX charges a 0.00% expense ratio, with no loads or transaction fees at Fidelity. The trade-off is that ZERO funds cannot be moved to another brokerage, so leaving Fidelity means selling first, which can create a tax bill in a taxable account.
Should I buy FZROX or FXAIX?
FZROX tracks the total U.S. market at 0.00%, while FXAIX tracks the official S&P 500 at 0.015%. The cost difference is pennies, so decide based on whether you want small-cap exposure and whether portability between brokerages matters to you.
What is the minimum to start investing in Fidelity index funds?
There is no minimum. Every Fidelity index mutual fund, including the ZERO funds and FXAIX, can be purchased with as little as $1, which makes Fidelity one of the easiest places to start investing small amounts.
Are Fidelity index funds good for retirement accounts?
They are widely used in IRAs because the combination of $0 minimums and rock-bottom fees leaves more money compounding. The ZERO funds' transfer restriction also matters less inside an IRA. As with any investment, returns are not guaranteed and depend on the market.
