ETFs / Evergreen
Two ETFs can multiply the same exposure.
A weighted example shows why fund count is different from diversification.
Combine underlying weights, not just the number of funds, when learning to measure overlap.
Look through the holdings
Investor.gov notes that a mutual fund or ETF is not necessarily diversified, especially when it focuses on a narrow sector. Even broad funds can overlap. Buying a second wrapper does not automatically introduce a new source of risk or return. A look-through analysis asks how much of the total portfolio ultimately depends on each holding or common economic factor.
Calculate one company's combined weight
Suppose a fictional portfolio puts 60% in Fund A and 40% in Fund B. Company X represents 10% of A and 25% of B. Its combined portfolio weight is 0.60 × 0.10 plus 0.40 × 0.25, or 16%. Merely averaging the two fund weights would produce 17.5%, which is wrong here because the portfolio allocations are unequal.
Names are not the only overlap
Two funds can own different companies but still depend heavily on the same country, industry, currency, or financing conditions. Conversely, a company listed in one country may sell to customers worldwide. Holdings overlap is therefore one useful lens, not a complete risk model. Correlations can also change, especially during market stress, so an apparent historical offset is not a guarantee.
Make the exercise reproducible
Record the date of each holdings file, the portfolio allocation used, and whether the list covers all positions or only the largest ones. Missing holdings should be marked unknown rather than treated as zero. The calculation explains exposure under stated assumptions. It does not determine an appropriate concentration limit or recommend replacing any particular investment.
A global perspective
Fund disclosure frequency, naming conventions, derivatives use, and currency hedging differ. Use the correct share class and dated holdings when comparing actual documents.
Sources & further reading
Investor.gov — Asset allocation and diversification ↗Sources checked Oct 15, 2026. Examples are original illustrations. No affiliation with cited organizations.
Make the idea stick.
Mark complete when you are ready. Reaching the end alone does not mark a lesson complete.
What assumption in this guide would change the result in a different situation? Revisit the example and explain that change in your own words.
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