How to Find Overlap in Your ETFs

ETF overlap is the degree to which two or more funds you own hold the same underlying stocks. Every ETF is a basket of companies, and different funds often reach for the same leaders, so the same name can sit inside several of your funds at once. When that happens, your true exposure to those companies is the sum across all of them, not what any single fund shows.

The reason this matters is diversification. Most people hold several funds precisely so that no single company or sector can sink the whole portfolio. Overlap works against that goal without announcing itself: on paper you own many funds and hundreds of stocks, but if the same dozen names dominate the top of each fund, a rough stretch for those names hits everything you hold at once. You are less diversified than the ticker count implies.

Overlap is not automatically a mistake. Sometimes you want a core position in the largest companies, and some overlap is unavoidable. The point is to see it clearly and decide it on purpose, rather than discover after a drawdown that most of your money was riding on the same few stocks.

You can find most of your overlap with the funds’ own fact sheets and a bit of patience. The steps below go from the easiest signal to the ones that hide.

• 1. List each fund’s top holdings. Pull up the top-10 holdings for every ETF you own (each fund’s fact sheet or provider page lists them). Write the names down side by side so you can scan across funds, not just within one.
• 2. Look for names that repeat. Scan for the same companies appearing near the top of more than one fund. The usual culprits are the largest mega-cap names, which anchor many broad and large-cap funds. Repeated names are your overlap.
• 3. Check for shared index exposure. Two funds tracking related indexes will own many of the same stocks even if their names sound different. A total-market fund and an S&P 500 fund, for example, share most of their weight. Note which of your funds draw from the same universe.
• 4. Watch the S&P 500 and Nasdaq-100 double-count. The biggest technology companies sit near the top of both an S&P 500 fund and a Nasdaq-100 fund. Holding both stacks extra weight on the same leaders rather than adding new exposure, and it is one of the most common hidden overlaps.
• 5. Add in your single stocks. Any company you hold directly and also own inside your ETFs counts twice. A stock that looks like a small direct position can be a large total position once its weight inside your funds is included.
• 6. Step back to the whole portfolio. Add it up: which few names carry an outsized share of your total across funds and direct holdings? That total is the real answer to how concentrated you are, and it is what overlap ultimately becomes.

Some free web tools let you enter two fund tickers and see their shared holdings, which speeds up steps one and two for a single pair. They handle two funds at a time, though, so the whole-portfolio view in steps five and six is still on you unless a tool can read all your holdings at once.

Checking overlap by hand works, but it is tedious once you own more than two or three funds, and it is easy to miss the single stocks that also live inside your ETFs. This is where AI tools help, and they split into two kinds worth keeping straight.

• General chatbots (ChatGPT, Claude, and similar). These can compare funds well if you paste in their top holdings, and they will point out the repeated names and explain the concentration. The catch is that they cannot see your accounts, so you have to assemble and paste the holdings yourself, and you should verify any specific figures they state.
• Connected assistants (Walnut). A connected assistant reads your real holdings through your linked brokerage, so it already knows the funds and single stocks you own. You can ask where your portfolio concentrates and which names repeat across funds without building the lists by hand.

Walnut is the connected kind, and to be upfront, since this is our site, it leads only in that narrow lane rather than overall. Walnut is an AI investing assistant you chat with on the broker you already own. It connects your existing brokerage through SnapTrade, read-only by default, reads your real holdings, and frames each one against the S&P 500, so you can ask about overlap and concentration in plain language and see it across everything you hold at once. You approve every trade, and Walnut is not an investment adviser. For the broader category, see AI portfolio analysis tools.

Everything above adds up to one thing: how much of your money rides on a few names. Overlap across funds, plus any single stocks you also hold, becomes concentration in a handful of companies, even when your ticker list looks long. Finding overlap and measuring concentration are two views of the same question, and it is worth looking at both.

For the wider version of this, see how to check portfolio concentration, which looks at how much of your total sits in your largest positions. And if you are deciding between two specific funds in the first place, see how to compare ETFs, which covers holdings, cost, and what each fund actually gives you.

Owning several ETFs is not the same as being diversified. If the same mega-cap names anchor the top of each fund, and especially if you hold both an S&P 500 and a Nasdaq-100 fund, your portfolio can ride on far fewer bets than the ticker count suggests. To find your overlap, compare each fund’s top holdings, note shared index exposure, watch the large-cap and tech double-counting, and add in your single stocks. You can do it by hand with fund fact sheets, lean on a general chatbot by pasting your holdings in, or use a connected assistant like Walnut that reads your real holdings and frames each against the S&P 500. Whichever you choose, the goal is the same: know your overlap so you can decide it on purpose. Walnut is not an investment adviser.