ETF Overlap
Calculator

What is ETF overlap and why does it matter?

ETF overlap occurs when two or more ETFs hold the same underlying stocks. Australian investors often hold multiple ETFs like VAS, VGS, and NDQ without realising they share large positions in the same US mega-cap tech companies.

Three ways to measure overlap

This calculator shows overlap three ways. The Holdings tab shows stock-level overlap using the minimum weight method. The Country tab shows how much of each ETF is allocated to the same countries — useful for spotting unintended US concentration. The Sector tab shows GICS sector breakdowns side-by-side so you can see if you're doubling up on Information Technology across multiple funds.

Common high-overlap pairs on the ASX

VGS and IVV typically show 60–70% holdings overlap because both are dominated by US large caps. NDQ and IVV overlap around 55–65% due to heavy Nasdaq weighting in the S&P 500. VAS and A200 share nearly 95% of holdings, making them near-identical. From a country perspective, VGS and NDQ both have 70%+ US allocation — even if the specific stocks differ, the country concentration compounds.

What overlap is acceptable?

There is no universal rule, but as a guide: below 20% is low and generally fine for diversification; 20–40% is moderate and worth monitoring; above 40% suggests significant duplication that may not be intentional.