FILE / IVV-FXAIX
2026 edition
ROCK-BOTTOM S&P 500 PAIR
IVV vs FXAIX: the cheapest S&P 500 funds compared
FXAIX is one of the lowest-cost S&P 500 mutual funds anywhere, but only at Fidelity. IVV is iShares' ETF alternative, available at any brokerage.
LIVE SEC DATA / FIG. 0
From the most recent N-CSR filings on SEC EDGAR
Both funds are registered investment companies under the Investment Company Act of 1940 (15 U.S.C. §§ 80a-1 et seq.) and elect RIC status under 26 U.S.C. § 851. The ETF operates under SEC Rule 6c-11 (17 CFR 270.6c-11), authorising in-kind creation and redemption under 26 U.S.C. § 852(b)(6). The mutual fund prices daily at NAV under Investment Company Act § 22(d) (15 U.S.C. § 80a-22(d)).
Cross-verify any figure on SEC EDGAR by entering each fund's CIK; see the methodology page for refresh cadence and the full source ledger.
QUICK VERDICT
read this if nothing elsePick the ETF if
You are not at Fidelity, want ETF tax efficiency in a taxable account, or want a fund that travels with you to any brokerage.
Pick the index fund if
You are at Fidelity and want the lowest-cost S&P 500 mutual fund available, with $0 minimum and easy auto-invest.
FXAIX runs at roughly 0.015%, among the lowest expense ratios on any mainstream S&P 500 fund. The catch: it is a Fidelity proprietary fund, only available in Fidelity accounts. IVV from iShares (BlackRock) charges around 0.03%, the same as VOO, and is available at every brokerage. Between IVV and VOO the choice usually comes down to ecosystem preference. Between IVV and FXAIX the choice is wrapper plus brokerage.
Expense ratios are typical figures from each issuer's published prospectus. Fidelity has trimmed FXAIX's expense ratio over time and may revisit again. Confirm current figures on the Fidelity and iShares product pages.
FIG. A / SPEC SHEET
Side by side
FIG. B / HOW FIDELITY KEEPS FXAIX SO CHEAP
Securities lending plus scale
Index funds at scale generate revenue beyond the expense ratio: short sellers borrow holdings (especially small caps and high-volatility names), and the fund collects a fee. Fidelity uses some of that revenue to subsidise expense ratios on flagship index products like FXAIX and the FZROX zero-fee fund. The economics also depend on the fund being a client retention tool inside Fidelity's broader business: 401(k) administration, advisory, cash management. Free or near-free index funds are how Fidelity wins household relationships, then earns from cross-sell.
The practical takeaway: FXAIX is a fine fund, run by a major issuer, that you can hold without worrying about subsidies disappearing overnight. Just remember it is not portable. Leave Fidelity and you cannot transfer FXAIX in kind to another brokerage. You would need to liquidate, which is fine in an IRA but creates a taxable event in a brokerage account.
FIG. C / SHOULD I CONSIDER VOO OR SPY INSTEAD
Three other S&P 500 options worth knowing
VOO
The other major S&P 500 ETF. Around 0.03%. Same cost as IVV. Best fit when staying inside its home brokerage.
SPY
The original S&P 500 ETF (1993). Around 0.09%. More expensive than VOO/IVV but extreme liquidity for active trading.
SWPPX
Schwab's S&P 500 mutual fund. Around 0.02%. Schwab-only equivalent of FXAIX, $0 minimum.
For long-term buy-and-hold, the order of preference goes by expense ratio and ecosystem fit: FXAIX or SWPPX inside their respective brokerages, IVV or VOO if you want a portable ETF, SPY only if you specifically need its liquidity for trading.
DESK Q&A
Frequently asked
Q01Is FXAIX really cheaper than VOO?
Yes, on stated expense ratio. FXAIX runs at roughly 0.015%, VOO at roughly 0.03%. The difference is about 1.5 basis points. On a $100,000 holding for one year that is roughly $15. Real, but small. The bigger question is whether Fidelity is your preferred brokerage, because FXAIX only lives there.
Q02Can I transfer FXAIX to a non-Fidelity brokerage?
No. FXAIX is a Fidelity proprietary mutual fund and cannot be transferred in kind to another firm. To leave Fidelity holding FXAIX, you would need to sell the position. In a taxable account that creates a capital gains event. In an IRA the sale is tax-free, but you still have to wait for settlement and re-buy at the destination.
Q03Why is IVV the same price as VOO?
BlackRock and the other major issuers have been in a long-running price war on S&P 500 ETFs and have converged at the 0.03% level. Both offer essentially identical products tracking the same index. The differences come down to ecosystem preference (BlackRock partnerships versus the cooperative-issuer model) and tracking error, which is small on both.
Q04Should I switch from VOO to IVV or vice versa?
No. Switching between near-identical S&P 500 ETFs in a taxable account would realise capital gains on the position you sold, costing you more in taxes than any expense ratio difference would ever recover. Pick one and hold. If you have already chosen poorly enough that switching matters, you have other portfolio issues to address first.