Two ETFs Can Hold the Same Stocks, So Check the Overlap

“Do these two ETFs hold the same stocks?”

Often, more than you’d guess. A broad large-cap fund, a growth fund, a quality fund and a technology fund can each carry the same handful of very large companies near the top of their holdings, because those companies are big enough and profitable enough to qualify for all four. The names on the funds differ. The top of the holdings list may barely change from one to the next.

Two hypothetical funds

Take two funds, X and Y. Each has a different name and a different stated approach. Here are their largest holdings.

Holding	Fund X weight	Fund Y weight
Company A	8%	10%
Company B	7%	5%
Company C	6%	none
Company D	none	6%

A and B appear in both. C is only in X, D only in Y. Nothing in either fund’s name would tell you that both have the same company as their single largest position.

Measuring the overlap by weight

The usual way to measure overlap by weight is to take each company the two funds share and count the smaller of its two weights. That smaller weight is the slice both funds genuinely have in common. Then add those slices up.

Thirteen percent from the top four lines alone. Each fund has hundreds of smaller holdings beneath these, and many will be shared too, so the full figure is usually higher once every line is counted. A holdings file with every position lets you do the whole calculation, and a spreadsheet makes it quick: list both funds, match the tickers, take the smaller weight for each match, and sum.

What you actually own

The overlap percentage is one view. The more useful one is your combined exposure to each company, because that is what moves your account.

You bought two funds to spread your money around. Nine percent of the portfolio now rides on one company. Fifteen percent rides on two. If Company A reports a bad quarter, both funds fall together, and the second fund you bought for diversification gives you almost none on that particular stock.

This is the concentration that shows up in a narrow rally. When a few mega-cap names drive the whole market, every fund that holds them near the top moves in step, and a portfolio that looked like several different ideas behaves like one. It also means your portfolio returns are more sensitive to a few names than the fund count suggests.

Where to find the holdings

Every fund publishes a fact sheet, usually a short document on the issuer’s website with the top holdings, sector split, expense ratio and a few statistics. The top-ten list on the fact sheet is where to start, and the walkthrough on reading an ETF fact sheet covers the rest of it.

For the full picture, go to the fund’s page on the issuer site and look for a complete holdings file. Many issuers post it as a downloadable spreadsheet and update it regularly. Check the as-of date. Weights drift as prices move, and an index fund’s holdings change at each rebalance, so compare two files dated close together.

Some research tools have an overlap feature that does the matching for you. It is a convenience. The method underneath is the same smaller-weight sum, and running it once by hand makes it easy to check what a tool is showing.

Two bets or one bigger bet

The practical question is what you meant to buy. If you added Fund Y believing it gave you a different kind of exposure, and it turns out to repeat Fund X’s largest positions, you haven’t diversified. You’ve doubled down on the same companies with a second expense ratio.

A few checks help before buying a second fund. Line up the top ten holdings of both. Compare the sector weights. Look at the index each one tracks and read its rules for how stocks get in and how they are weighted, since two indexes built on different ideas can still end up owning the same companies whenever the largest firms in the market happen to qualify under both sets of rules.

What to do when the overlap is bigger than you wanted

Start with the combined weights, since they tell you where the risk sits. Then pick a fix.

The cleanest is to sell one fund. If Y repeats X at the top and adds little underneath, you keep the cheaper or broader of the two and put the money somewhere that actually behaves differently: another region, smaller companies, a different asset class, or simply cash until you know what you want.

Resizing is the second option. Holding less of the overlapping fund shrinks the doubled positions without removing them. In the example, moving to $15,000 in X and $5,000 in Y brings Company A down to $1,200 + $500, or $1,700, which is 8.5% of the same $20,000. Small change. Overlap at the top of two funds is stubborn, because both hold those names heavily.

The third is to replace one fund with an equal-weight or small-cap version of a similar idea. Those funds hold the same large companies at much smaller weights, or not at all, and the combined exposure drops accordingly.

When overlap is fine

Overlap is a problem only when you didn’t intend it. Some investors want heavy exposure to the largest companies and hold a broad fund plus a sector fund on purpose, knowing the top names repeat. Others use a second fund to tilt the portfolio toward a factor, accepting that the underlying stocks overlap while the weights differ. Both are reasonable choices.

The point of measuring is to make it a choice. Know the combined weight in each of your biggest names, decide whether you’re comfortable with it, and then keep both funds or drop one.

Holding three or more funds, or individual stocks alongside them? Checking ETF overlap across a whole portfolio extends the same sum to every fund and direct holding you own.