Cheapest S&P 500 Index Funds in 2026, Ranked by Expense Ratio

Fidelity 500 Index Fund (FXAIX) has the lowest expense ratio of the seven S&P 500 index funds on this list, at 0.015% a year, or $15 on $100,000 held for one year. It has no purchase minimum. Vanguard's and iShares' S&P 500 ETFs charge 0.03%, and Vanguard's 500 Index Admiral Shares (VFIAX) charges 0.04% and asks for a $3,000 minimum. The figures below were read from each fund company's own pages and filings in October 2026.

What an expense ratio is

An expense ratio is a fund's yearly running cost, written as a share of the money it holds. The fund pays it out of its assets, so you never receive a separate bill. At 0.015%, a fund takes $1.50 a year for every $10,000 invested, which makes the ratio easy to check against your own balance. Every fund states this figure in the fee table of its prospectus, and that table is where the figures on this page come from.

Seven S&P 500 funds, sorted by what they charge

Every fund here tracks the S&P 500, so the fee is what separates them. The table sorts the funds by expense ratio. The two cost columns multiply that ratio by a balance held for one year.

Our analysis: on fee alone, FXAIX is the cheapest choice, but its margin over the next fund is small. FXAIX costs $1.50 a year on $10,000, and SPLG costs $2. The real spread sits at the bottom of the table, where VFINX's 0.14% is about nine times FXAIX's ratio.

This page ranks the seven S&P 500 funds whose 2026 expense ratios are confirmed on the fund company's own pages or filings. Schwab's S&P 500 Index Fund is therefore not ranked here.

Three checks before you buy

1. Confirm the ratio on the fund's current page. The figures here are dated, and a fund can lower its fee after this page was checked.
2. Check the minimum or the share price. A mutual fund sets its own minimum. An ETF costs the market price of one share, so that price is the real entry cost.
3. Look for overlap. A total US stock market fund already holds most of the same large companies, so adding an S&P 500 fund beside it doubles up on those stocks rather than adding new exposure.

Which fund fits which buyer

The ranking points to a different fund depending on what you need from it, and the fee is only one part of that choice.

• The lowest fee with no starting minimum: FXAIX. It is the cheapest fund in the table and the only one with no purchase minimum.
• The lowest fee in an ETF: SPLG. It ranks second overall at 0.02%, and its net asset value was $91.07 on October 8, so one share is the entry cost.
• A Vanguard mutual fund on the S&P 500: VFIAX at 0.04%, which asks for a minimum, or VFINX at 0.14%. Both follow the same index, so the higher fee in VFINX buys no different exposure.

Nothing in this list says which of these fits your account. It only shows what each one charges and what it asks you to pay to start.

What a fee gap costs over ten years

A fee comes out of the return every year, so a small gap compounds. The table assumes a hypothetical 7% gross return a year, with each fund's fee deducted from that return. It shows what the fee costs in ending value over ten years, compared with the same money earning the full 7%. The 7% is an illustration, not a forecast, and the figures scale in proportion to any balance.

Our analysis: on that balance, the gap between FXAIX and VFINX is $125 a year, because the two ratios differ by 0.125 percentage points. Over ten years that gap becomes $2,283 of ending value. The gap grows in proportion to the balance, so the same switch on a balance one-tenth as large saves one-tenth as much.

The wrapper changes the minimum, not the fee

The cheapest fund is a mutual fund, but the next two cheapest are ETFs, and VFIAX, a mutual fund, charges more than VOO and IVV. Judge the funds by their expense ratio, not by whether they are ETFs or mutual funds.

The wrapper still changes what you pay to get in. Vanguard's page for VOO lists a $1 investment minimum, but an ETF is bought in shares, and one share of VOO carried a $715.54 net asset value on October 9, 2026. One share of SPLG was $91.07 on October 8, and one share of SPY was $773.77. Fidelity's FXAIX has no purchase minimum at all, while both Vanguard mutual fund classes on this list require the minimum shown in the table.

Our analysis: FXAIX is the only fund here with both the lowest ratio and no minimum. A buyer who wants a mutual fund without a starting minimum has one choice on this list. A buyer who prefers an ETF pays the market price of one share, and the expense ratio is still the number to compare.

What the table does not measure

This page measures the expense ratio and the minimum, and nothing else. It does not measure how closely a fund follows the S&P 500, how much tax a fund creates in a taxable account, or any commission or spread your broker adds when you buy an ETF. A fee table shows what running the fund costs. It does not show what the fund earns for you.

If the fund sits inside a robo advisor, that advisor's fee comes on top of the fund's expense ratio. The robo advisor ranking lists those layers, and the Wealthfront and Betterment comparison shows how a single S&P 500 sleeve is priced inside those services. To buy ETFs without a trade commission, the free investing apps list the $0 online trade fee on US ETFs at each broker. If the cash between purchases needs a home, money market accounts and money market funds are compared on their own page.

FAQ

What is the cheapest S&P 500 index fund in 2026?

Fidelity 500 Index Fund (FXAIX) is the cheapest of the seven funds checked, at 0.015% a year, which is the lowest fee in the table. It is a mutual fund with no purchase minimum.

Is an S&P 500 ETF cheaper than an S&P 500 mutual fund?

Not in this table. SPLG at 0.02%, and VOO and IVV at 0.03%, are ETFs, but FXAIX at 0.015% is a mutual fund and costs less than all three. VFIAX, also a mutual fund, costs 0.04%, which is more than VOO and IVV. Compare the expense ratios, not the structure.

How much does a 0.14% fee cost each year?

It costs $14 a year on $10,000 invested. Over ten years at a hypothetical 7% gross return, that fee takes $2,559 of ending value from a $100,000 balance, based on our calculation rather than a forecast.

Does the S&P 500 fund with the lowest fee have a minimum?

No. FXAIX states that there is no purchase minimum for fund shares in its summary prospectus dated April 29, 2026. VFIAX and VFINX each ask for $3,000 to start. An ETF is bought one share at a time, so its entry cost is the share price.

Do the seven funds hold the same stocks?

They track the same index, so their holdings are close to the same 500 large US companies. The differences shown on this page are the expense ratio and the minimum, not the companies you own.

Why is Schwab's S&P 500 fund missing from this list?

The ranking includes only funds whose 2026 expense ratio is confirmed in the fund company's own documents. Schwab's S&P 500 Index Fund does not meet that test in this update, so it is left out rather than estimated.

Will these expense ratios stay the same?

They can change. This page is checked again every 60 days, and the fund's own page is the place to confirm the current ratio and minimum before you buy.

Methodology and sources

• Expense ratios come from the fund company's own page or filing: Fidelity 500 Index Fund summary prospectus, dated April 29, 2026, SPDR Portfolio S&P 500 ETF, Vanguard S&P 500 ETF, iShares Core S&P 500 ETF, Vanguard 500 Index Admiral Shares, SPDR S&P 500 ETF Trust and Vanguard 500 Index Investor Shares.
• Dates: the Fidelity figure is from its April 29, 2026 prospectus. The iShares fee is as stated as of August 31, 2026. The Vanguard and SPDR prices are net asset values dated October 8 or 9, 2026.
• Arithmetic: the yearly cost is the balance times the expense ratio. The ten-year figures grow the balance at 7% gross with the fee deducted each year, then compare that with the same money at 7% and no fee.
• Refresh: every 60 days, or sooner if a fund company changes a fee.

This page is general information, not personalized financial advice. Confirm the current expense ratio and minimum with the fund provider before you invest.