How to read an ETF factsheet
Last updated August 2026
Short answer
It takes two minutes to read and prevents the most common portfolio error, which is buying three funds that hold the same twenty companies.
Start with the index
The named index determines what the fund holds, how positions are weighted and what is excluded.
Two funds described as total market can track indexes with different small-cap coverage and different inclusion rules.
Market-cap weighting is the default, and equal-weighted or factor-tilted alternatives behave differently enough that the label alone is not sufficient.
The expense ratio, in context
Broad index ETFs are widely available under 0.10% a year, and several sit near zero.
Sector, thematic and actively managed ETFs charge considerably more, and the question is whether the exposure justifies it.
The comparison that matters is against funds tracking a similar index, not against the market as a whole.
Top holdings and concentration
The top ten holdings with their weights, and frequently the share of the fund those ten represent.
That figure is what tells you whether a fund of 500 names is diversified or is largely a bet on a handful of them.
Checking it across the funds you already own is how you find the overlap that makes a portfolio less diversified than its fund count suggests.
Try it in Walnut
Walnut connects to your brokerage and can show where two funds you hold contain the same companies, which no single factsheet reveals.
Tracking, size and spread
Tracking difference against the index shows whether the fund delivers what it promises, net of costs.
Assets under management matter because very small funds can be closed, forcing a sale at a time you did not choose.
The bid-ask spread is a per-trade cost that is negligible on widely held funds and material on niche ones.
Yield figures
A trailing twelve-month yield reports distributions already paid.
The 30-day SEC yield is standardised and forward-looking, which makes it the better basis for comparing two funds.
Reading which is quoted matters, because the two can differ substantially for a bond fund in a period of changing rates.
What to check elsewhere
Tax structure, particularly for commodity, currency and futures-based funds, which can be taxed unlike ordinary equity ETFs.
The full prospectus for strategy constraints, use of derivatives and securities lending policy.
Your own portfolio, since the most useful question about any fund is what it adds to what you already hold.
A two-minute routine
Read the index, then the expense ratio, then the top ten and what share of the fund they represent.
Compare those top holdings against the funds you already own, which is where overlap becomes visible.
Check assets under management and the spread if you plan to trade rather than hold, since both are costs that do not appear in the expense ratio.
Sources
Fund documents including factsheets and prospectuses are filed with the SEC and available through EDGAR full-text search, with general ETF guidance at investor.gov. Walnut is informational and is not an investment adviser. This guide is educational and not personalized investment advice.
FAQ
What is an ETF factsheet?
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A one or two page summary published by the fund provider: the index tracked, the expense ratio, top holdings, sector and country breakdown, assets under management, and recent performance. It is the fastest way to understand what a fund holds.
What should I look at first?
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The index. Everything else follows from it, and two funds with similar names frequently track indexes with different inclusion rules, weightings and coverage.
Why do the top ten holdings matter?
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Because they show concentration a headline holding count hides. A fund holding 500 companies can have a third of its money in ten of them, which makes it a very different investment from what the number suggests.
What is tracking difference?
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The gap between the fund's return and the index it follows, caused by fees, cash drag and sampling. Small and consistent is normal; large or erratic means the fund is not doing its one job well.
Does fund size matter?
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Somewhat. Very small funds can be closed by the provider, which forces a taxable sale in a taxable account. Larger funds also tend to trade with tighter spreads, which reduces the cost of buying and selling.
What is the bid-ask spread?
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The gap between what buyers offer and sellers ask, and it is a real cost each time you trade. Widely held funds have narrow spreads; niche ones can have wide ones that dwarf the expense ratio for an active trader.
Is the yield figure reliable?
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Read what it measures. A trailing twelve-month yield describes the past; a 30-day SEC yield is a standardised forward-looking measure. Comparing one against the other across two funds compares different things.
What does the factsheet not tell me?
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The tax treatment of the structure, which matters for commodity and currency funds, and anything about whether the price is reasonable. For those, the prospectus and the market are the sources.
What is the fastest way to use one?
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Index, expense ratio, top ten and their combined weight. Then compare those holdings against the funds you already own. That routine takes two minutes and catches both the cost question and the overlap that makes a portfolio less diversified than it looks.