ETF overlap: how to see whether your ETFs hold the same stocks

What is ETF overlap?

Overlap is the part of your funds that invests in the same stocks. A global ETF already holds hundreds of US companies. If you add an S&P 500 ETF, you largely buy the same companies again. You then own two funds, but not twice the diversification.

In a global equity ETF, often well over two thirds of the money is in US companies, with the largest tech firms at the top. Combine it with an S&P 500 ETF and a Nasdaq ETF, and the same tech companies count three times.

Why it matters

Overlap is not wrong, but it should be a deliberate choice. Without noticing, a large share of your wealth can depend on a handful of companies or one sector. If that sector falls, you feel it in all your funds at once.

Check your overlap in four steps

1. List all your ETFs, with the amount you hold in each fund.
2. Look up each ETF's factsheet. It shows the largest holdings (top 10) and the split by country and sector.
3. See which companies appear in more than one fund. The more names in the top 10 match, the larger the overlap.
4. Work out how much you hold in each company in total: for each fund, add up your amount × that company's weight.

What you can do with it

• For every extra ETF, ask: what does this fund add that I do not have yet? Think of other regions, smaller companies or bonds.
• Decide for yourself how much you want to hold at most in one company, sector or country.
• Include individual stocks next to your ETFs: they add up with your ETF positions.

There is no right or wrong amount of overlap. What matters is that you know how your portfolio is really built.