How index funds work
Meet the market, one basket at a time.
An index fund seeks to track a specified benchmark. Its holdings, costs and tracking method matter more than the label alone.
An index is a set of rules
A benchmark defines which securities belong and how they are weighted. A market-capitalization-weighted index gives larger companies more influence. A fund that tracks that benchmark may buy its components or use a representative sample.
A basket is not automatically diversified
A broad market index and a narrow sector index can have very different risks. Check the largest holdings, sector concentrations and geographic exposure. Owning two funds does not add much diversification if they hold mostly the same securities.
Compare the details
Look at the expense ratio, trading costs, tracking difference and the benchmark methodology. An index fund can fall in value with its market, and low fees do not remove that risk. This guide explains the structure; it does not select a fund for your circumstances.
Try the idea
Compare a hypothetical 5% gross annual return with the same return reduced by a constant cost drag. Real fund tracking and costs are more complex.
View values
Two funds own almost the same holdings. Does owning both ensure diversification?
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