Is there a free alternative to ETF Research Center’s Fund Overlap?
ETF Research Center details checked September 14, 2026
Yes, for pair overlap: the PortLens ETF overlap checker compares two funds free and with no account, and a portfolio scan adds your combined company exposure across up to 20 typed holdings. Fund Overlap is free to use too, so the difference is scope rather than price. Both tools answer “how much do these funds overlap?”, and they offer both pair and portfolio workflows. ETF Research Center’s Fund Overlap compares two equity ETFs and points to Portfolio Builder for multiple funds. PortLens combines a pair checker with a scan of your typed stocks and ETFs. Pair overlap and your combined company exposure answer different questions.
What is ETF Research Center?
It is an ETF research site, run by AltaVista Research, whose best-known free tool is Fund Overlap. Its own page describes that tool as showing which holdings any two equity ETFs have in common along with the top differences in exposure, and points readers to its Portfolio Builder for overlap across more than two funds. Its subscriptions page lists a $0 Basic tier and paid Individual and Professional tiers at $29 and $99 a month, each opening with a one-month free trial. The overlap tool itself tells a signed-out visitor that it is showing the top five shared holdings and that the complete list needs at least a free membership. All of that was read from the site's own pages on September 14, 2026.
Why is a portfolio-wide number different from a pairwise one?
Because overlap between two funds says nothing about what a third fund adds. Pairwise overlap is the sum, over every company both funds hold, of the smaller of its two weights — a complete answer about those two funds and silent about everything else you own. A portfolio-wide look-through instead multiplies each company's weight inside every fund by that fund's weight in the portfolio and adds the same company up across all of them, including shares you hold directly. That is what turns “these two are 85% alike” into “one company is 9% of everything I own”.
PortLens publishes both. The ETF overlap checker takes two tickers and needs no account, with curated pairs such as QQQ vs VOO carrying their own pages and their own as-of dates. A scan does the portfolio-wide version. How both are computed is on the methodology page, and why two overlap checkers disagree on the same funds explains why a percentage means nothing without the definition behind it.
What does each one measure?
| Question | PortLens | ETF Research Center |
|---|---|---|
| How many funds at a time? | Two in the overlap checker; a portfolio scan takes every holding you enter, up to 20 of them without an account. | Two equity ETFs in Fund Overlap. The tool points to Portfolio Builder for overlap across more than two. |
| What does an account cost? | None for the overlap checker. A scan runs signed out at up to 20 typed holdings, and a longer list takes a free account. | Basic membership is $0. Individual is $29 a month and Professional $99 a month, each starting with a one-month free trial. |
| How much of the shared-holdings list is free? | The ten largest shared positions by overlapping weight, plus a count of every shared holding, on a curated pair page and a checker result alike. The full list is published nowhere. | The tool shows the top five to a signed-out visitor and asks for at least a free Basic membership for the complete list. |
| Does it screen and rate funds? | No. | Yes — an ETF finder, an equity screener, fundamentals and valuation data, and its own ETF ratings. |
| Does it handle non-equity funds? | Partly. A fund’s bonds, cash and derivatives are shown by type (US Treasury, government agencies, corporate bonds and so on), and its bonds count in geography by their own country. There is no fixed-income analysis such as yield, duration or credit quality, and the stated look-through coverage is an upper bound rather than a measure of completeness: a fund no holdings can be listed for is what pulls that figure down. | Fund Overlap is described for equity ETFs; expanded fixed-income metrics are listed under the paid tiers. |
What will PortLens refuse to answer?
A pair it cannot list at least 25 constituents for on both sides gets a stated refusal naming the fund that fell short, rather than a number computed from a partial list, which would understate overlap badly. Two tickers the SEC identifies as share classes of one registered fund get a declared 100% with no constituent arithmetic. Where a fund's SEC filing is the source, its holdings can be weeks or months old, the two funds need not share a date, and the result is anchored to the older of the two and prints both. Refusing is the point: a confident wrong number is worse than a stated gap.
Where ETF Research Center does more than PortLens
ETF Research Center is a fund research product, and most of what it does has no PortLens equivalent at all. Its own site lists an ETF finder, an equity power screener, fundamentals and valuation data, watchlists across dozens of criteria and its own ETF ratings. PortLens has none of that: it analyses a portfolio you already hold and does not help you pick a fund.
Its paid tiers also reach places PortLens does not — expanded fixed-income metrics, complete searchable and exportable holdings for a stated list of issuers, downloadable tear sheets, and a portfolio builder that tests all-ETF portfolios against a benchmark of your choosing. Where PortLens is narrower on purpose, that is a scope choice, not a claim to do more.
How do I look through my own portfolio?
Enter tickers and share counts; PortLens calculates the position weights. It runs free and without an account for up to 20 typed holdings; a longer list takes a free account. A scan shows how much of your money it could open up into companies; a fund counts as opened even when its published list is partial. The fund-cost figure names any fund with no published fee rather than counting it as free. What each figure means and how it is computed is on the methodology page. All investing involves risk, including possible loss of principal, and past performance does not guarantee future results.
Key takeaways
- Both compute fund overlap from real constituent lists; the difference is scope, not method.
- Fund Overlap covers two equity ETFs per check, and its own tier table lists Portfolio Builder — the route it gives for more than two — under its paid plans.
- PortLens answers two funds free and without an account, and a scan looks through a whole portfolio at once — up to 20 typed holdings signed out, and a longer list on a free account.
- For picking funds rather than examining ones you hold, ETF Research Center does a great deal PortLens does not attempt.
Other comparisons
This article is for information and education only and is not investment advice. Analytics referenced are computed as described in our methodology; see our disclosures.