Wealthy PotFXAIX vs SPY: Same S&P 500, One-Sixth the Fee, Different Way to Buy It
FXAIX and SPY both track the S&P 500. FXAIX is Fidelity's index mutual fund at 0.015% a year; SPY is State Street's 1993 exchange-traded trust at 0.0945%, a little over six times as much. Over the ten years to 31 December 2025 FXAIX returned 14.81% a year and SPY 14.66%, against 14.82% for the index, so FXAIX kept almost all of the market's return and SPY gave up 0.16 points a year. The portfolios are the same 500 companies. The real decision is the wrapper: FXAIX buys and sells once a day at its closing price with no minimum and is simplest inside a Fidelity account or 401(k); SPY trades all day on an exchange at any broker. If you hold for the long run at Fidelity, FXAIX is the cheaper way to own the same thing.
Table of Contents
The Short Answer
- Fees: FXAIX 0.015%, SPY 0.0945%. On $10,000 that is $1.50 a year against $9.45.
- Ten-year returns to 31 December 2025: FXAIX 14.81%, SPY 14.66% a year. The S&P 500 returned 14.82%. Both figures come from each fund's own prospectus, for the same dates.
- FXAIX stays ahead after taxes too: 14.30% against 14.21% a year over ten years after taxes on distributions, on the SEC's standard method.
- Same stocks. 99.8% of FXAIX's weight was in companies SPY's index holds. The overlap tool shows 94.5% only because the two holdings snapshots are a month apart (more below).
- FXAIX is a mutual fund. Orders fill once a day at the NAV calculated at the 4 p.m. Eastern close, and its prospectus says "There is no purchase minimum for fund shares."
- SPY is an exchange-traded unit investment trust. It trades all day at market prices through any broker, cannot lend its securities, and holds dividends in cash until each quarterly payout.
- Do not own both. It is the same index twice.
Same Index, Same Stocks
FXAIX's prospectus says it normally invests "at least 80% of assets in common stocks included in the S&P 500® Index." SPY's trust holds "as many of the Index Securities as is practicable." Same index, so the same companies at the same weights.
Our Portfolio Overlap Checker shows 94.5% for this pair, and it is worth explaining why that is lower than you would expect. The tool works from each fund's SEC holdings report (Form N-PORT). Fidelity's latest one is dated 31 May 2026. SPY files no N-PORT at all, so the tool uses IVV's S&P 500 holdings at 30 June 2026 in its place. Stock prices moved in that month: Microsoft was 5.14% of FXAIX on 31 May and 4.29% of the S&P 500 on 30 June; Micron went the other way, 1.68% to 2.02%. The tool counts those drifts as non-overlap.
The cleaner test is the one that does not depend on dates: 99.8% of FXAIX's weight sat in companies that are in the S&P 500 portfolio. And the same-date return figures below show the two funds separated by little more than their fee difference. Treat these as the same portfolio.
FXAIX vs SPY Side by Side
| FXAIX | SPY | |
|---|---|---|
| Full name | Fidelity 500 Index Fund | State Street SPDR S&P 500 ETF Trust |
| Index | S&P 500 | S&P 500 |
| Expense ratio | 0.015% | 0.0945% |
| Annual cost on $10,000 | $1.50 | $9.45 |
| Type | Open-end mutual fund | Exchange-traded unit investment trust |
| How you buy | At the day's closing NAV, in dollar amounts | On an exchange during market hours, at market prices |
| Minimum | None, per the prospectus | The price of one unit, about $764 (NAV, 1 Oct 2026), unless your broker sells fractions |
| Holdings | 507 (28 Feb 2026) | 505 (1 Oct 2026) |
| Size | $749.4 billion (28 Feb 2026) | $817.6 billion (1 Oct 2026) |
| Securities lending | Yes | Not permitted |
| Dividends paid | April, July, October, December | Quarterly, last business day of the month after each ex-date |
| FXAIX capital gains paid | April and December, if any | |
| Automatic dividend reinvestment | Default option at Fidelity | "No dividend reinvestment service is provided by the Trust"; brokers may offer one |
SPY's fee includes a trustee waiver that runs "until February 1, 2027." We will recheck it after that date.
What the Fee Gap Has Cost
Both prospectuses print the SEC's standard return table for periods ended 31 December 2025, and both print the identical S&P 500 line, so this is a like-for-like comparison.
| Average annual total return to 31 Dec 2025 | 1 year | 5 years | 10 years |
|---|---|---|---|
| FXAIX, before taxes | 17.86% | 14.41% | 14.81% |
| SPY, before taxes | 17.73% | 14.28% | 14.66% |
| S&P 500 | 17.88 | 14.42 | 14.82 |
| FXAIX minus SPY | +0.13 | +0.13 | +0.15 |
| FXAIX behind the index | 0.02 | 0.01 | 0.01 |
| SPY behind the index | 0.15 | 0.14 | 0.16 |
| FXAIX, after taxes on distributions | 17.51 | 14.02 | 14.30 |
| SPY, after taxes on distributions | 17.41 | 13.91 | 14.21 |
| Tax drag, FXAIX | 0.35 | 0.39 | 0.51 |
| Tax drag, SPY | 0.32 | 0.37 | 0.45 |
FXAIX tracked the index almost perfectly; SPY lagged by more than its fee. The fee gap is 0.08 points a year, and the ten-year return gap is 0.15. SPY's trust rules explain part of the rest: it cannot lend securities for income, and it holds dividends in a non-interest-bearing account until the quarterly payout. Neither issuer publishes a breakdown, so we do not assign numbers to each cause.
The tax line is the one place SPY looks better, and it is not enough. FXAIX gave up 0.51 points a year to taxes on distributions over ten years, SPY 0.45. Neither filing explains the difference, and we do not guess at it. Even after those taxes, FXAIX finished ahead: 14.30% against 14.21% a year. If you hold either fund in an IRA or 401(k), the tax line does not apply at all.
| Hypothetical $10,000 held for 10 years | Ending value |
|---|---|
| At SPY's 10-year return (14.66%) | $39,275 |
| At FXAIX's 10-year return (14.81%) | $39,792 |
| Difference | about $517 |
Fidelity's own fiscal-year report adds a later window: to 28 February 2026, FXAIX returned 15.49% a year over ten years against 15.50% for the S&P 500, again a gap of one hundredth of a point. Run your own contribution schedule through the compound interest calculator.
This is educational information, not personalized investment advice. Past performance does not guarantee future results, and all investing carries the risk of loss.
Mutual Fund vs ETF: How Each One Trades
FXAIX prices once a day. Fidelity "normally calculates NAV as of the close of business of the NYSE, normally 4:00 p.m. Eastern time," and "Shares will be bought at the NAV next calculated after an order is received in proper form." Place an order at 10 a.m. or 3 p.m. and you get the same closing price. You buy in dollars, so $50 buys $50 of the fund, and there is no bid-ask spread to pay.
There are rules against quick round trips. Fidelity counts a "roundtrip" when you sell within 30 days of buying. "Shareholders with two or more roundtrip transactions in a single fund within a rolling 90-day period will be blocked from making additional purchases or exchange purchases of the fund for 85 days." For an investor who buys monthly and holds for years, this never comes up.
Where you hold it matters. The prospectus lists buying through "a Fidelity® brokerage or mutual fund account, through a retirement account, or through an investment professional," and warns that "you may be charged a transaction fee if you buy or sell shares through a non-Fidelity broker." Whether another broker carries FXAIX, and what it charges, is up to that broker; check before you buy.
SPY trades like a stock. You can buy or sell at any moment the market is open, at whatever price the market sets, through any brokerage account. That is useful for traders and for anyone who wants a limit order or a stop. The cost is a small bid-ask spread on each trade and a structure that, as above, gives up a little return each year. SPY's legal form is covered in detail in IVV vs SPY.
Which One Fits You
You have a Fidelity brokerage account or IRA: FXAIX. It is the lowest-cost of the two by a wide margin, it tracked the index to within a hundredth of a point, you can invest any dollar amount, and dividends reinvest automatically by default.
Your 401(k) menu includes FXAIX: use it for your S&P 500 slice. A 401(k) can only offer what is on its menu, so SPY would be reachable only through a brokerage window if your plan has one, and FXAIX does the same job for a sixth of the fee.
You use a broker other than Fidelity: check whether it offers FXAIX without a transaction fee. If not, a low-cost S&P 500 ETF is usually simpler than either, and SPY is the most expensive of the main ones. Compare SPY vs SPYM (0.02%), SPY vs VOO and FXAIX vs VOO.
You trade during the day or need intraday orders: SPY, or another S&P 500 ETF. A mutual fund cannot do this.
Large taxable account, long horizon: the filings show SPY with slightly lower tax drag but FXAIX still ahead after taxes. If you already hold one with big gains, selling to switch probably costs more in tax than it saves. Check your 2026 tax bracket first.
Other Fidelity choices. Fidelity's zero-fee funds and total-market funds are compared in FZROX vs FXAIX, FSKAX vs FXAIX and FXAIX vs VTI.
Sources & Methodology
- Fidelity 500 Index Fund Summary Prospectus, 29 April 2026: the 0.015% fee table, strategy, lending, no purchase minimum, and returns to 31 December 2025.
- Fidelity Concord Street Trust, Form 485BPOS filed 24 April 2026: FXAIX's full prospectus, including NAV timing, the excessive trading policy, non-Fidelity broker fees and the distribution schedule.
- Fidelity Concord Street Trust, Form N-CSR for the year ended 28 February 2026: FXAIX's fund size, holdings count, turnover and fiscal-year returns.
- SPDR S&P 500 ETF Trust, Form 485BPOS filed 26 January 2026: SPY's 0.0945% expense accrual, structure, restrictions, dividend handling and returns to 31 December 2025.
- State Street's SPY page: assets, NAV per unit and holdings count as of 1 October 2026.
- FXAIX Form N-PORT for 31 May 2026 and IVV Form N-PORT for 30 June 2026: the holdings behind the overlap figures.
How the overlap was computed. The Portfolio Overlap Checker sums the smaller of the two weights for each shared security. SPY files no N-PORT, so IVV's S&P 500 holdings stand in for it, and Fidelity's latest filing is a month earlier than IVV's. Both effects are explained above.
What we could not verify. We did not check which non-Fidelity brokers carry FXAIX or what they charge, or which 401(k) plans offer it; those are specific to each firm. We quote no bid-ask spread or trading-volume figure for SPY.
This article is for general education and is not investment, tax or legal advice. Past performance does not guarantee future results, and all investing carries the risk of loss. Figures were checked against the sources above on 4 October 2026; verify current figures with each issuer before acting.
FAQ: FXAIX vs SPY
Is FXAIX the same as SPY?
Same index, different wrapper. Both track the S&P 500. FXAIX is a Fidelity mutual fund that prices once a day; SPY is an exchange-traded unit investment trust that trades all day.
Which is cheaper, FXAIX or SPY?
FXAIX, at 0.015% a year against SPY's 0.0945%. On $100,000 that is $15 against $94.50 a year.
Has FXAIX done better than SPY?
Yes, by about the cost difference and a little more. Over ten years to 31 December 2025, FXAIX returned 14.81% a year and SPY 14.66%, with the index at 14.82%.
Is SPY more tax-efficient than FXAIX?
Slightly, on the prospectus numbers: ten-year tax drag on distributions was 0.45 points for SPY and 0.51 for FXAIX. FXAIX still ended ahead after those taxes, 14.30% against 14.21% a year.
Is there a minimum to buy FXAIX?
No. Fidelity's prospectus says "There is no purchase minimum for fund shares." SPY's minimum is one unit, about $764 at NAV on 1 October 2026, unless your broker sells fractional shares.
Can I buy FXAIX outside Fidelity?
Possibly, but the prospectus warns you may pay a transaction fee through a non-Fidelity broker. Check your broker's fund list and fee schedule first.
Should I own both FXAIX and SPY?
No. They hold the same S&P 500 companies. Owning both adds nothing but a second line and a higher average fee.
Which is better in a Roth IRA?
At Fidelity, FXAIX: lower cost, no minimum, and the tax-efficiency question does not apply inside a Roth. Elsewhere, a low-cost S&P 500 ETF usually beats SPY on cost.
Cite This Page
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"FXAIX vs SPY: Same S&P 500, One-Sixth the Fee, Different Way to Buy It." Wealthy Pot, 2026. https://wealthypot.com/fxaix-vs-spy/
Related comparisons: FXAIX vs VOO · IVV vs SPY · SPY vs VOO · SPY vs SPYM · FZROX vs FXAIX · VTI vs VOO · All ETF comparisons
