How to compare ETFs: holdings, overlap and costs
An ETF is a fund whose shares trade on an exchange. Its name can suggest a theme, but its holdings and rules reveal what you actually own. Two funds with different branding can contain many of the same companies.
A hypothetical overlap
Imagine Fund A places 20% in Company X and Fund B places 30% in it. Investing $1,000 in each creates $500 of combined exposure to X within a $2,000 allocation, or 25%. Holding two funds did not remove that concentration.
Read the holdings date, index methodology and weighting rules. Market-cap weighting and equal weighting can produce different portfolios even when they begin with the same list of companies.
Compare the trading instrument too
Check ongoing expenses, bid-ask spread and any purchase costs. The exchange price can differ from the value of the underlying assets per share. A narrow-looking fee comparison does not include every execution cost.
Keep holdings and costs together in your market research. Verify whether a comparison uses price returns or total returns that account for distributions.
Inspect the fund’s domicile, currency exposure and documentation for your jurisdiction. A trading currency alone does not describe the currencies of the underlying businesses.
Leveraged and inverse products need a separate reading of their objectives and reset period. Do not assume every ETF follows the behaviour of a conventional broad-market fund.
For practice, calculate overlap between two hypothetical funds before comparing their recent charts. That exercise identifies what you are comparing without making a recommendation to buy either.