How to check mutual fund portfolio overlap from filings

Checking mutual fund portfolio overlap means comparing two schemes' disclosed holdings for the same month and measuring how much of each portfolio sits in the same stocks. You do not need a paid dataset to do it. Indian AMCs are required to publish full scheme portfolios every month, in a downloadable spreadsheet, on their own website and on the AMFI website. Once you have two of those files for the same month-end, the calculation is arithmetic.

Where the data comes from

Mutual funds in India disclose full portfolios of all their schemes on a monthly basis on the AMC website and on the AMFI website, within 10 days from the close of each month, in a user-friendly and downloadable spreadsheet format. The half-yearly portfolio is published within 10 days of the half-year close, and that version carries the ISIN and yield of the instruments.

On the AMFI site, monthly portfolio disclosures are listed by AMC rather than by scheme, so you download an AMC-level file and find your scheme inside it. Each AMC also keeps the same files on its own investor-disclosures page. Both are free.

The method, step by step

1. Fix one date. Pick a month-end and use that month's file for both schemes. Comparing different months produces a number that means nothing.
2. Pull both portfolios. Download the AMC spreadsheets from AMFI or each AMC's site. Keep the raw files; you will want to re-check a weight later.
3. Match on ISIN, not on name. Company names are written inconsistently across AMCs, and share classes and DVR shares are separate securities. The ISIN is the identifier that matches cleanly.
4. Use the percentage-of-net-assets column, not the market value. Two schemes of different sizes are only comparable by weight.
5. Take the minimum weight per common holding. For each ISIN present in both, record the lower of the two weights. That is the part of the portfolios genuinely doing the same job.
6. Sum the minimums. The total is the overlap as a percentage of net assets. Two schemes each holding a stock at 6 percent contribute 6 points; if one holds 6 percent and the other 2 percent, they contribute 2.
7. Exclude non-equity lines from the equity comparison. Cash, treps, government securities and other cash-management lines are not stock positions, and leaving them in inflates or deflates the answer depending on the schemes. Note what you excluded.

Two schemes from the same AMC often share a research process, so overlap between them tends to be higher than between houses. That is a fact about the input data, not a judgement about either scheme.

Some overlap is now disclosed for you

Since SEBI's circular on categorisation and rationalisation dated 26 February 2026, you do not always have to compute this yourself. The circular capped the portfolio of a sectoral or thematic scheme at 50 percent overlap with other equity schemes of the same fund house, and required overlap to be computed quarterly, as the average of daily overlap values, and disclosed monthly on the AMC's website.

Two caveats before you rely on the published figure. It exists for the categories the rule covers, not for every pair of schemes you might want to compare, so the manual method above is still the general answer. And a disclosed quarterly average of daily values is a different statistic from a single month-end comparison, so do not read the two as interchangeable. What the rule changes and which categories it binds is covered in mutual fund scheme categorisation.

What the number does not tell you

• It is not a measure of similar returns. Identical stocks at different weights, bought at different times, do not produce identical outcomes. Overlap measures holdings, not behaviour.
• It is a snapshot. The portfolio is a month-end position published up to 10 days later. Between disclosures, funds trade and the true overlap moves.
• It says nothing about suitability. Overlap is a descriptive statistic about two disclosed portfolios. Whether either scheme belongs in a portfolio is a decision for you or a SEBI-registered adviser, not something an overlap percentage answers.
• Debt and hybrid schemes need care. Instrument-level maturity and yield matter there, which is why the half-yearly disclosure with ISIN and yield is more useful than a bare holdings list.

Where to go next

Once you have the monthly portfolios in hand, they answer more than the overlap question. The same files show which mutual funds are buying a stock when you read them across AMCs instead of across schemes, and they are the raw input behind any mutual fund portfolio tracker. For the scheme's own documents, the factsheet carries monthly summary data while the scheme information document carries the mandate that shaped the portfolio in the first place, and the total expense ratio is disclosed separately from holdings.

Flock reads primary filings and disclosures and stamps every data point with its source and date, so you can see how old a holding is before you use it. Computing mutual fund portfolio overlap tells you what two schemes held on one date. What that means for you is your call to make. This is not investment advice.