When people search for a Fidelity S&P index ETF, they often mean one of two things. They either want Fidelity's own S&P 500 fund, which is actually a mutual fund called FXAIX, or they want an S&P 500 ETF they can buy inside a Fidelity brokerage account, such as SPLG or SPY.
This guide covers both. You will see how FXAIX works, which S&P 500 ETFs you can trade at Fidelity, and how brokers like Robinhood compare for the same kind of investing.
Why People Mix Up FXAIX and ETFs
Fidelity is best known for its mutual funds. The firm's flagship S&P 500 product, FXAIX, is technically a mutual fund, not an ETF. Many investors still search for a Fidelity S&P index ETF because they want low-cost S&P 500 exposure and they assume Fidelity offers an ETF version. The closest match is to use a third-party S&P 500 ETF inside a Fidelity account.
FXAIX, Fidelity's S&P 500 Mutual Fund
FXAIX is the Fidelity 500 Index Fund. It tracks the S&P 500 and holds the same 500 stocks in roughly the same weights.
Key Facts on FXAIX
- It is a mutual fund, so it prices once per day after the market closes.
- The expense ratio is very low, around 0.015 percent per year as of 2026.
- There is no minimum to open a position inside a Fidelity account.
- It is widely used inside 401(k) plans.
How FXAIX Trades
You place an order during the day, and your buy or sell fills at that day's closing price. You cannot day-trade FXAIX, and you cannot use limit orders the way you can with an ETF.
Robinhood
Robinhood
Robinhood is a trading platform that brings stocks, ETFs, options, futures, prediction markets, crypto, and retirement accounts together in one app.
Standout feature
One platform for stocks, ETFs, options, futures, prediction markets, and crypto
Fees
$0 commission on stocks, ETFs, and options.
Pros
Zero-commission trading on stocks, ETFs, and options
Cons
Best perks (high APY, lower margin rates) require Gold subscription ($5/month)
S&P 500 ETFs You Can Trade at Fidelity
A Fidelity brokerage account lets you trade most US-listed ETFs without commission. That includes the major S&P 500 funds.
SPLG
SPLG is the SPDR Portfolio S&P 500 ETF from State Street. It has a very low expense ratio, around 0.02 percent per year. The share price is lower than SPY, which can make it easier to buy whole shares in small amounts.
SPY
SPY is the SPDR S&P 500 ETF Trust, also from State Street. It was the first US ETF and is one of the most traded securities in the world. The expense ratio is about 0.09 percent, higher than newer competitors. Active traders still use SPY for its huge daily volume.
IVV and VOO
These are the iShares Core S&P 500 ETF (IVV) and the Vanguard S&P 500 ETF (VOO). Both have very low expense ratios and are widely held by long-term investors. You can buy either through a Fidelity account or through other brokers, including Robinhood.
FXAIX vs S&P 500 ETFs
Here is how the trade-off usually plays out.
Fees
FXAIX is one of the cheapest options at about 0.015 percent. SPLG is close at 0.02 percent. VOO and IVV are around 0.03 percent. SPY is the most expensive of these at about 0.09 percent. All are still low compared to most actively managed funds.
Trading Style
FXAIX only trades at end-of-day prices. The ETFs trade live throughout the day. For long-term investors who buy and hold, this difference rarely matters much. For someone who likes live prices or limit orders, the ETF feels more flexible.
Where You Can Hold It
FXAIX is mainly available inside Fidelity accounts and many 401(k) plans. SPLG, SPY, IVV, and VOO can be bought at almost any US broker, including Robinhood. If you want one product you can hold across different brokers, an ETF is easier.
Tax Efficiency
ETFs are often slightly more tax efficient than mutual funds in regular taxable accounts. Inside an IRA, 401(k), or other tax-advantaged account, this gap matters less. A tax professional can help if you are weighing this decision.
Returns and Risk
All of these products track the S&P 500. Their returns are very close year to year, with small gaps from fees and dividend handling. The index has had long periods of growth and also sharp drops, including in 2008 and early 2020.
An S&P 500 fund is lower risk than holding a single stock, since you own 500 companies at once. It is not safe in absolute terms. The index can fall 20 percent or more in a bad year. Past performance does not guarantee future results.
How to Buy Through Fidelity or Another Broker
A simple path looks like this.
- Open a brokerage account at Fidelity, Robinhood, or another broker.
- Fund the account with a transfer from your bank.
- Search for the ticker you want, such as FXAIX, SPLG, SPY, IVV, or VOO.
- Place a market or limit order for ETFs, or a dollar amount for FXAIX.
- Set up recurring buys if you want to add to the position over time.
Many brokers, including Robinhood, offer fractional shares, so you can start with a small dollar amount and add more later.
Who These Funds Suit
Low-cost S&P 500 funds tend to suit long-term investors who want broad US stock exposure with minimal fees. They are often used as a core piece of a wider plan that also includes bonds, international stocks, and cash.
They may not suit someone who needs the money in the next year or two. Stock markets can drop sharply, and short time frames do not pair well with that kind of risk. Talk with a financial advisor if you are unsure how to size your position.
Frequently Asked Questions
Is FXAIX an ETF?
No. FXAIX is a mutual fund, not an ETF. It tracks the S&P 500 and prices once per day after the market closes. If you want an ETF that tracks the same index, look at SPLG, IVV, VOO, or SPY.
Can I buy FXAIX on Robinhood?
No. Robinhood does not currently offer mutual funds like FXAIX. You can buy similar S&P 500 ETFs on Robinhood, such as VOO, IVV, SPLG, or SPY. To buy FXAIX you usually need a Fidelity account or a 401(k) that offers it.
Which is cheaper, FXAIX or VOO?
FXAIX has a slightly lower expense ratio, around 0.015 percent versus 0.03 percent for VOO. On a 10,000 dollar position, that is roughly a 1.50 dollar per year difference. Both are very low cost.
Are S&P 500 ETFs safe?
They are lower risk than buying one stock since you own 500 companies. They are not safe in absolute terms. The index can fall sharply during recessions and market panics, and past performance does not guarantee future returns.
