Fund overlap calculator
Published 2026-10-01
Two funds with different names can hold the same stocks. Enter two to five fund tickers and the size of the portfolio: this reads each fund's own SEC filings and reports what they hold in common, the largest single stock you own through them, and what their expense ratios cost a year.
How this is calculated
Each fund files its complete portfolio with the SEC on Form N-PORT. A holding's weight is its share of that fund's reported portfolio value, and two holdings are the same security when the filing gives them the same CUSIP (or an ISIN that contains it). The portfolio is modelled as an equal amount in each fund you enter.
- Overlap between two funds is the sum, over every security both hold, of the smaller of its two weights. 100% means identical portfolios; 0% means no security in common. With more than two funds the page shows every pair.
- Largest single-stock exposure adds a stock's weight through every fund that holds it, divided by the number of funds, and multiplies by your portfolio value. Only equity holdings count as stocks. Names are as filed.
- Cost is the average of the funds' expense ratios, as each fund published it, applied to your portfolio value for one year.
What is left out, and why
A fund appears in the figures only when the SEC has its holdings and it has published an expense ratio. Otherwise it is listed with the reason and takes no part in any number: a money-market fund files Form N-MFP rather than N-PORT, so its holdings are not available here; a ticker that is not an SEC-listed fund, such as a single stock, is not recognised. Nothing is estimated or shown as zero.
N-PORT is filed quarterly and published with a delay, so each fund's holdings carry the date they are as of. Holdings can have changed since. The figures use no prices, returns or ratings and nothing from a market-data vendor; they are arithmetic on public filings and on the number you type.