FXAIX vs. VFIAX: Fidelity 500 Index Fund or Vanguard 500 Index Fund Admi?
Figures last verified October 31, 2026
Two S&P 500 funds from the two biggest names in indexing. Identical 500 stocks, near-identical returns; the contest is fee and minimum.
| FXAIX | VFIAX | |
|---|---|---|
| Fund | Fidelity 500 Index Fund | Vanguard 500 Index Fund Admiral Shares |
| Family | Fidelity | Vanguard |
| Category | S&P 500 / Large Blend | S&P 500 / Large Blend |
| Type | Index | Index |
| Expense ratio | 0.015% | 0.04% |
| Cost per $10k/yr | $1.50 | $4 |
| Minimum | $0 | $3,000 |
| Strategy | Tracks the S&P 500 index of the 500 largest US companies. | Tracks the S&P 500 — the 500 largest US companies, about 80% of total US market value. |
FXAIX edges it on paper — 0.015% versus 0.04%, no minimum versus $3,000 — but both are so cheap the difference is lunch money per year. Your brokerage decides this one.
About FXAIX
FXAIX is what happens when index investing becomes a commodity and price wars do their work: the S&P 500, tracked with surgical precision, for 0.015% — a dollar fifty per year on a $10,000 balance — with no minimum investment. There is no catch in the fund itself. Fidelity loses money or close to it here and earns it back when you eventually use their other services.
About VFIAX
This is the direct descendant of the first index fund ever sold to the public — Jack Bogle's 1976 'folly' that now anchors trillions of dollars in retirement money. VFIAX holds the S&P 500 in its market weights and charges 0.04% to do it. Over the decades, that simple recipe has beaten the large majority of professionally managed large-cap funds, which is either embarrassing for the profession or liberating for you, depending on where you sit.
Whichever you pick, the principle is the same one that runs through this whole site: minimize cost, hold for decades, ignore the noise. See how both stack up against the field in our best index funds by category, or run the numbers yourself with the expense ratio calculator.
Expense ratios and minimums drawn from fund provider documentation; last verified October 31, 2026. Editorial opinion, not investment advice. Confirm figures against the official prospectus before investing.