Two exchange-traded funds can advertise similar ongoing expenses and still cost different amounts to buy, hold, and sell.
The expense ratio is useful. It is not a complete description of the transaction.
For a clearer comparison, separate the fund's own expenses from the price available in the market and any charges made by an intermediary. This article explains those concepts for general education; it does not recommend a fund or a trading strategy.
First, understand the ongoing expense
A fund's expense ratio expresses certain annual operating expenses relative to its assets. Those expenses affect the fund's assets and investor returns; they are not ordinarily a separate invoice arriving once a year.
The SEC's investor guidance distinguishes ongoing operating expenses from other fees and costs. Read the actual prospectus fee table and any conditions attached to an expense waiver rather than relying on a rounded advertising figure. [1]
For a deliberately simplified illustration, 0.20 percent of a constant $5,000 holding is $10 over a year. Real balances change, expenses accrue through the fund, and other costs can apply. This is arithmetic, not a quotation for an available fund or a return forecast.
Next, look at the trading spread
An ETF trades on an exchange. The available buying price and selling price can differ; that difference is the bid-ask spread.
Investor.gov explains that ETF investors may face trading costs in addition to fund fees and describes where to find information such as a fund's median spread. [2]
Suppose a fictional quote shows a $49.98 bid and a $50.02 ask. The spread is four cents per share. Buying 100 shares at the ask would cost $5,002 before other charges; immediately selling those shares at the unchanged bid would produce $4,998. The $4 difference illustrates a transaction friction, not a predicted loss for a real trade.
Quotes can change, orders may execute differently, and a historical median spread does not guarantee the price available at the moment you act.
Distinguish market price from underlying value
An ETF's market price can be above or below its net asset value. These differences are described as premiums and discounts.
That comparison is separate from the expense ratio and the bid-ask spread. A low annual operating expense does not guarantee that a particular purchase happens at underlying asset value. [2]
When reading a premium-or-discount figure, check its calculation time and the source of the underlying values. A number taken from yesterday's closing data does not establish the value of a live quote today.
Include the account and intermediary
Check the brokerage's transaction, account, currency-conversion, and other applicable charges. "Commission-free" describes one potential charge, not every possible cost.
Taxes depend on the investment, account, jurisdiction, and individual circumstances. They are outside the simplified illustrations here. Do not compare two products as though every investor will have the same after-tax result.
Also compare what the funds actually hold and the risks they take. A cheaper product tracking a different market is not a like-for-like alternative solely because both are called ETFs.
Build a comparison you can inspect
For each candidate, record the investment objective, holdings or index, ongoing expense, waiver terms, historical spread information, premium-or-discount information, and relevant account charges. Save the dates and source documents.
Where something is unclear, leave the cell unresolved and ask the issuer or intermediary. Avoid turning a missing fee into an assumed zero.
The purpose of this exercise is to understand the product and the transaction. It does not establish whether an ETF fits your goals or make its returns predictable. Price is part of that decision; so are exposure, risk, and how the investment would be used.
Sources
[1] SEC Investor Bulletin: Mutual Fund and ETF Fees and Expenses (https://www.investor.gov/introduction-investing/general-resources/news-alerts/alerts-bulletins/investor-bulletins/mutual-fund-and-etf-fees-and-expenses-investor-bulletin)
[2] Investor.gov: Exchange-Traded Funds (https://www.investor.gov/introduction-investing/general-resources/news-alerts/alerts-bulletins/investor-bulletins-24)