63.41% US share. That is what the MSCI ACWI looked like at the end of April 2026. For an index that serves many investors as a particularly broadly diversified equity product, this is a one-sided distribution, because a world ETF is actually supposed to solve a very simple problem: nobody has to search for individual winners, nobody has to shift back and forth between France, Japan, India or the United States. One product bundles many companies from different countries, sectors and currency areas. For many private investors, this is the perfect foundation that simplifies long-term investing.
However, this simplicity now has a price: a world index does not distribute money evenly across countries, people or economic output. It weights by market value. Large listed companies get a lot of space, smaller companies get little. Countries with many highly valued corporations dominate. Countries with fewer listed flagships are weighted less heavily, even if they are economically strong.
In the MSCI ACWI, the 63.41% US share at the end of April 2026 was joined by 28.69% of companies from the technology sector. The ten largest positions together accounted for 24.62% of the index. NVIDIA, Apple, Microsoft, Amazon*, Alphabet, Broadcom, Taiwan Semiconductor, Meta and Tesla shaped the top. That is truly not a broadly distributed cross-section of the world. It is a global equity portfolio with a strong US tech focus.
The index follows market value
A market-capitalization-weighted index follows a simple calculation: the higher a company is valued on the stock market, the larger its share in the index becomes. If NVIDIA, Apple or Microsoft rise sharply, they are automatically weighted more heavily. If other companies fall behind, they lose weight and the effect reinforces itself. A world index like the MSCI does not check valuations, earnings and revenue figures or their future fantasies. It simply adopts the market’s prices.
This takes many decisions off investors’ hands: winners remain in the portfolio, losers shrink. Precisely for this reason, broad indices have made life difficult for many active strategies in recent years. But it is, as so often in life: success always brings obligations and responsibility with it and creates certain dependencies. Anyone buying a world ETF today is primarily buying the winners of recent years with a high weighting, and it is not entirely by chance that the United States is at the top. American stock exchanges are full of corporations that earn money worldwide. Software, cloud, semiconductors, platforms, digital advertising and AI infrastructure are developed to a large extent by US companies. Europe does have strong industry, good brands and some niches, but on the stock market many companies cannot keep up with the size and valuation of the American platform corporations.
Technology is not only in the technology sector
The 28.69% show only part of the technology load. Amazon* is not counted as part of the classic technology sector. Alphabet and Meta are classified under communication services. Tesla is also assigned differently. Nevertheless, these business models depend on software, data, platforms, computing power, automation and digital advertising. A look at the MSCI sector table therefore appears to show many industries. At second glance, however, many of the largest positions depend on similar expectations: high margins at platform companies, rising cloud revenues, more data centers, strong demand for chips and further growing AI spending.
That was a gift for investors in recent years. Anyone holding a broad world ETF automatically had the big tech winners in the portfolio. Nobody had to pick NVIDIA or Microsoft years ago. The index weighted these winners ever more heavily as prices rose. The same effect works against the portfolio in weak phases. If the largest stocks disappoint, it is not just a small theme area that falls. Then the entire world index moves with it. Weaker AI fantasy, pressure on platform margins or political interventions against market power land directly in the basic investment of many investors.
The world economy and the world stock market are not the same thing
The world economy consists of factories, raw materials, ports, energy, workers, consumption and services. The world stock market consists of tradable companies with market prices. The two are often lumped together. India, for example, can become more important for global demand and still remain small in the index. Brazil can supply raw materials that are needed everywhere without appearing large in a world ETF. Germany can have strong machinery and car manufacturers and still barely approach the weight of American software corporations.
For the index, what matters is not how visible a country is in everyday life. What matters is how highly its listed companies are valued. Many investors buy a world ETF and think of the world economy. In reality, they are buying the listed world by market value.
More ETFs increase the problem
Many portfolios look broader than they are. A world ETF sits in the portfolio as the basis. Added to it are an S&P 500 ETF, a Nasdaq ETF, an AI ETF or a semiconductor ETF. On the screen, this looks like several building blocks. In terms of content, even more money often ends up in the same corporations. Anyone holding a world ETF already owns some of the major IT drivers. An additional US or tech ETF increases this weight further. Another ETF with this focus is then a clear decision in favor of US technology and not additional diversification for the portfolio.
Looking into your own portfolio
For private investors, a simple check is enough: How high is the US share? How large is technology really when platform companies outside the tech sector are included? Which ten positions have the highest weight? And what overlaps arise from additional ETFs? A world ETF remains a good basis for many investors precisely because it requires little maintenance. But such an ETF should never be bought blindly. Anyone who believes a global ETF is automatically balancedis making things too easy.
World ETFs are certainly not the problem. Rather, the problem is the wrong expectations of them. A global index fund is simple, cheap and broad enough to avoid many beginner mistakes, and thus certainly useful for long-term wealth building. But the name should not be reassuring, because at the end of April 2026 the MSCI ACWI contained significantly more United States than the rest of the world. Technology and platform companies shaped the top.
Anyone who knows this can deal with it cleanly…
