In the five years to September 2026, FXAIX returned 13.8% a year and VOO returned 13.8%, dividends reinvested. FXAIX is a mutual fund and VOO is an ETF, and both track the S&P 500. The choice is about how you buy and hold them more than about what they own.
For a representative saver about twenty years from retirement, investing in a taxable account: In this situation, FXAIX and VOO come out about even. Neither their known costs nor their last five years change the plan's success rate enough to matter.
With only the known costs — the same market for both funds, differing by fees and dividend tax — the money lasted in 98.1% of 10,000 simulated futures with FXAIX and 98.1% with VOO. Using each fund's own returns from October 2021 to September 2026 instead, the figures were 98.1% and 98.1%. Both funds were run against the identical sequence of market shocks.
How you buy them. An ETF trades on an exchange during the day at a market price. A mutual fund is bought and sold once a day at its closing value, usually through the company that runs it or a brokerage that offers it. Mutual funds can be bought in exact dollar amounts, which makes automatic investing simple.
Taxes outside an IRA. In a taxable account, ETFs generally pass fewer capital gains on to their holders than mutual funds do. Broad index mutual funds usually distribute little, but this simulation does not model capital-gain distributions at all. In an IRA or 401(k) the difference does not apply.
FXAIX tracks the S&P 500 — it holds the 500 large US companies in the index, weighted by size. VOO tracks the S&P 500 — it holds the 500 large US companies in the index, weighted by size.
FXAIX charges 0.01% a year and yields 1.04%; VOO charges 0.03% and yields 1.06%.
Returns and volatility are measured from monthly returns with dividends reinvested over 60 months — one sample from one market, and weak evidence for telling two broad funds apart, which is why the known-cost result is reported first. Dividends are taxed at 15% in a taxable account by default, the qualified rate most households pay; the page also shows the 0% and 20% brackets. It is the only tax modeled. A 3.8% net investment income tax can also apply to dividends once modified adjusted gross income passes $200,000 ($250,000 joint); it is not included. Retirement spending is held at 70% of income in today's dollars, and contributions exclude any employer match.
Their fees are both very low and they own the same companies. Pick the one your brokerage makes easiest to buy and reinvest; in a taxable account, the ETF structure is the usual tiebreaker.
Some other brokerages offer it, often with a transaction fee. VOO, as an ETF, can be bought at almost any brokerage without one.