How to Pick an S&P 500 Fund
Not all trackers of this benchmark are created equal.
The S&P 500 is synonymous with the US stock market. It represents the US large-cap stock universe and captures roughly 80% of total US
Its market-cap weighting scheme is a simple, cost-efficient approach where the size of a company dictates the size of the portfolio’s position. Because positions adjust automatically as prices change, turnover and trading costs stay low. Combined with typically lower fees, this has historically given S&P 500 index funds a durable performance edge over most active peers.
With dozens of S&P 500 trackers that all hold the same stocks, investors often assume they are interchangeable. However, small structural differences can meaningfully affect long-term returns.
15-Year Cumulative Total Return: S&P 500 vs. Average Large-Blend Fund
Fees, Fees, Fees
Because the portfolios are identical, the cheapest fund is almost always the best-performing fund. The chart below shows the clear relationship between a fund’s
State Street SPDR Portfolio S&P 500 ETF SPYM charges one of the lowest fees, and through February 2026, it had the best 10-year annualized performance.
S&P 500 Index Funds' Performance vs. Fees
ETF vs. Mutual Fund
The two main wrappers for these funds are exchange-traded funds and mutual funds. ETFs trade on an exchange throughout the day like a stock; mutual funds price once daily after the market closes.
There’s virtually no difference between the two vehicles for investors in nontaxable accounts, like health savings accounts, IRAs, or 401(k)s, assuming all distributions are reinvested. On top of that, investors often don’t have a choice between multiple S&P 500 funds to choose from in their retirement plans. Luckily, many institutional share classes that are available in employers’ 401(k) plans have razor-thin fees. Fidelity 500 Index FXAIX is a mutual fund available to any investor, and it charges only 0.015%.
The vehicle matters more for investors in taxable accounts. ETFs use an in-kind creation and redemption mechanism that generally avoids triggering capital gains distributions, giving them a tax efficiency edge. In fact, none of the four S&P 500 ETFs have paid out capital gains in the past 10 years.
Mutual fund capital gains distributions tend to be small, but not zero. Investors in taxable accounts will need to pay Uncle Sam on those distributions, even if they didn’t sell a single share. That’s a small but measurable drag on performance.
Mutual funds offer a unique operational advantage to advisors seeking the best execution for their clients. Since mutual fund orders execute at the end of the day, unlike the real-time trading of ETFs, all orders transact at the same price. Advisors trading across multiple accounts, without the infrastructure to do block trades, can trade for their clients without the headache of execution price differences across accounts.
SPY: A Trading Tool
Most investors are familiar with State Street SPDR S&P 500 ETF SPY, the first ETF offered on a US exchange circa 1993. It was set up as a unit investment trust, contrary to most modern-day ETFs, which are set up as open-end funds.
Unit investment trusts were the approved structure for the earliest ETFs. However, the structure comes with disadvantages: SPY can’t lend securities, can’t use derivatives to equitize cash, and must hold dividends in a non-interest-bearing account until the next quarterly distribution, creating a small but persistent cash drag. In addition, SPY’s 0.09% fee makes it more expensive than other ETF counterparts. The other three S&P 500 ETFs, Vanguard S&P 500 ETF VOO, iShares Core S&P 500 ETF IVV, and State Street SPDR Portfolio S&P 500 ETF, charge lower fees and don’t have SPY’s shortcomings. They’re a better alternative for long-term investors.
SPY remains a dominant trading vehicle for the S&P 500, but it’s rarely the best option for long‑term investors. Its first-mover advantage made it the choice for institutional traders and market makers, and that early adoption built a self-reinforcing popularity among traders that persists today. SPY’s trading volume in dollar terms was more than 8 times that of Vanguard S&P 500 ETF over the three months through February, despite it being smaller than the Vanguard fund.
The Best S&P 500 Trackers for Long-Term Investors
Picking a fund with the lowest fee is the best option for most long-term investors. Taxable investors should lean toward ETFs because of their tax advantage. Below are great S&P 500 trackers available to all investors, and further below are great choices if offered by an employer through a 401(k) plan.
S&P 500 Index Funds With No Investment Minimums
Below are great S&P 500 funds commonly available in employer-sponsored retirement plans.
S&P 500 Index Funds Commonly Available in Employer-Sponsored Plans
The author or authors own shares in one or more securities mentioned in this article. Find out about Morningstar’s editorial policies.
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