In the five years to September 2026, VOO returned 13.8% a year and IVV returned 13.8%, dividends reinvested. VOO and IVV track the same index. The simulation is here to show what that looks like: no measurable difference to a retirement plan, in any situation.
For a representative saver about twenty years from retirement, investing in a taxable account: In this situation, VOO and IVV 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 98.0% of 10,000 simulated futures with VOO and 98.0% with IVV. Using each fund's own returns from October 2021 to September 2026 instead, the figures were 98.0% and 98.0%. Both funds were run against the identical sequence of market shocks.
Same companies, same weights. Both funds hold the S&P 500 in proportion to company size. Their fees, yields and returns differ by amounts too small to show up in a retirement plan.
What actually decides it. Which brokerage you use. Some brokers make their own family’s funds easier to buy or reinvest in; beyond that, pick either and move on to a decision that matters.
VOO tracks the S&P 500 — it holds the 500 large US companies in the index, weighted by size. IVV tracks the S&P 500 — it holds the 500 large US companies in the index, weighted by size.
VOO charges 0.03% a year and yields 1.04%; IVV 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.
Not one that matters to a long-term investor. They track the same index at nearly the same cost, and simulated against a retirement plan they give the same result.
Not in a taxable account — selling to switch can realize a capital gain, which costs more than any difference between the two funds. In an IRA it is harmless but pointless.