ETF Overlap – Frequently Asked Questions
ETF overlap is calculated by:
- Identifying holdings that appear in both ETFs
- Comparing their portfolio weights
- Summing the shared exposure
The result is shown as a percentage representing how similar the ETFs are.
Weight-based overlap measures how much exposure two ETFs truly share, not just whether they hold the same stocks.
A holding with a higher weight has more impact on overlap than a small position. This provides a more accurate picture than simply counting overlapping holdings.
The number of overlapping holdings can be misleading on its own. What matters more is weight-based overlap.
Two ETFs may share many stocks with small weights, resulting in low overlap, while sharing just a few high-weight holdings can produce high overlap.
Neither! It depends on your goal. Higher overlap means ETFs are more similar. Lower overlap usually means better diversification.
Overlap may differ due to:
- Different data update schedules
- Different calculation methods
- How weights are handled
- How small or missing holdings are treated
Small methodology differences can change results.
Yes. The site supports multi-ETF comparisons using pairwise overlap calculations. Each ETF is compared individually against the others.
Holdings data is based on the most recent publicly available ETF disclosures and is updated monthly. Data may not reflect intra-month changes, rebalancing, or corporate actions until the next update.
ETFs may appear similar but:
- Track different indexes
- Use different weighting strategies
- Hold different numbers of stocks
- Focus on different sectors or factors
No. This site is for educational and informational purposes only and does not provide financial or investment advice.
Not yet. A future feature may allow users to create temporary custom ETFs or portfolios using non-overlapping holdings and custom weights.