Is Your Global Tracker 70% US Stocks? The AI Concentration Problem

Your "global" tracker is probably mostly American, and increasingly, it's mostly seven American companies.

What percentage of a global tracker is actually US stocks?

Around 65-70%. The most popular global equity index, the MSCI World, is approximately 70% US stocks as of early 2026. The FTSE All-World Index is around 63% US. Vanguard's VWRL and HSBC's global tracker follow similar splits. This weighting reflects the US making up the largest share of the global stock market by value, but the concentration has grown sharply over the past decade.

Most UK investors who hold a "global" tracker assume they're getting genuine global diversification. The reality is that if the US stumbles, your portfolio stumbles hard, because two-thirds of it is US by construction.

What is the "Magnificent Seven" and why does it matter?

The Magnificent Seven refers to seven huge US technology companies: Apple, Microsoft, Alphabet (Google), Amazon, Meta, NVIDIA and Tesla. Together, they now make up around 30-35% of the S&P 500 and roughly 20-25% of the MSCI World. This is a historically unusual level of concentration in a handful of companies, mostly driven by the AI boom and investor excitement about these firms' long-term earnings potential.

When you own a global tracker, you now indirectly own these seven companies as a very large slice of your portfolio. The "diversification" of owning thousands of stocks globally is partially an illusion when a few names dominate the weighting.

Why is this a concentration problem?

Because concentrated bets behave differently from diversified ones. When the Magnificent Seven rise, your portfolio rises sharply. When they fall, your portfolio falls sharply. This is exactly what happened in 2022, when tech stocks fell heavily and "global" trackers dropped with them. It's also what drove the 2023-2025 rally, when tech stocks ran hard and trackers ran with them.

For long-term investors, occasional volatility is acceptable. But if you thought you owned a genuinely diversified global fund, you probably didn't expect your returns to depend so heavily on the share price of a handful of US tech companies. The risk isn't that these companies are bad investments, it's that your portfolio is less diversified than you think.

Is this necessarily a bad thing?

Not automatically. The Magnificent Seven are genuinely profitable, globally dominant companies with strong earnings. They've earned their market position through real business performance, not just hype. If they continue to dominate their markets, a heavy weighting to them will continue to serve investors well.

The risk is twofold. First, their current valuations assume they keep growing fast. If earnings slow, their share prices could fall sharply and take index funds down with them. Second, historical market leaders rarely stay leaders forever. The top seven companies by market cap in 2000 (Microsoft, GE, Cisco, Walmart, Exxon, Intel, NTT) looked invincible at the time. Only one remains in the top seven today.

How can you reduce this concentration if you want to?

Several ways. First, you can add an equal-weight global tracker to your portfolio, which gives every company the same weight regardless of size. This reduces the dominance of the largest companies. Second, you can hold a specific "ex-US" or "ex-Magnificent-Seven" fund alongside your main global tracker to tilt away from the biggest names.

Third, you can allocate a portion of your portfolio to emerging markets, European, UK or Japanese equities to rebalance away from the US. Fourth, some investors add small-cap or value-focused funds, which are typically underrepresented in standard cap-weighted trackers.

Should you rebalance out of global trackers entirely?

Probably not. Standard cap-weighted global trackers are still one of the simplest, lowest-cost ways to invest long-term, and the diversification across thousands of companies is real even with US concentration. The question is whether you want to accept the current concentration or actively tilt away from it.

A reasonable compromise is to keep a global tracker as your core holding (say 70-80% of your equity exposure) while adding a smaller allocation to regions or strategies that rebalance away from US mega-caps. This preserves the simplicity of index investing while reducing single-country, single-sector risk.

Where Mona Fits

Mona's Stocks and Shares ISA gives you access to diversified global investing with a clear view of what you actually own. Transparency about concentration (which companies, which countries, which sectors) matters more as markets become more top-heavy. Mona helps you build a long-term portfolio while staying aware of the structural risks inside seemingly "passive" funds, so you're not surprised by how it behaves when markets move.

The Bottom Line

A typical global tracker is around 70% US equities and 20-25% concentrated in seven US technology companies. This isn't automatically bad, but it's more concentrated than most investors realise. If the Magnificent Seven stumble, your "global" portfolio stumbles with them. Options for reducing concentration include equal-weight trackers, ex-US funds and regional diversification. Most investors are fine keeping a global tracker as a core holding, but understanding what's actually inside it matters more as market concentration grows.

Know what's really in your portfolio. Start investing with transparency through Mona today.

For impartial information and guidance on investing, visit MoneyHelper.org.uk.

Join Mona’s early access waitlist

Join the waitlist

All articles

Is Your Global Tracker 70% US Stocks? The AI Concentration Problem

Your "global" tracker is probably mostly American, and increasingly, it's mostly seven American companies.

What percentage of a global tracker is actually US stocks?

Around 65-70%. The most popular global equity index, the MSCI World, is approximately 70% US stocks as of early 2026. The FTSE All-World Index is around 63% US. Vanguard's VWRL and HSBC's global tracker follow similar splits. This weighting reflects the US making up the largest share of the global stock market by value, but the concentration has grown sharply over the past decade.

Most UK investors who hold a "global" tracker assume they're getting genuine global diversification. The reality is that if the US stumbles, your portfolio stumbles hard, because two-thirds of it is US by construction.

What is the "Magnificent Seven" and why does it matter?

The Magnificent Seven refers to seven huge US technology companies: Apple, Microsoft, Alphabet (Google), Amazon, Meta, NVIDIA and Tesla. Together, they now make up around 30-35% of the S&P 500 and roughly 20-25% of the MSCI World. This is a historically unusual level of concentration in a handful of companies, mostly driven by the AI boom and investor excitement about these firms' long-term earnings potential.

When you own a global tracker, you now indirectly own these seven companies as a very large slice of your portfolio. The "diversification" of owning thousands of stocks globally is partially an illusion when a few names dominate the weighting.

Why is this a concentration problem?

Because concentrated bets behave differently from diversified ones. When the Magnificent Seven rise, your portfolio rises sharply. When they fall, your portfolio falls sharply. This is exactly what happened in 2022, when tech stocks fell heavily and "global" trackers dropped with them. It's also what drove the 2023-2025 rally, when tech stocks ran hard and trackers ran with them.

For long-term investors, occasional volatility is acceptable. But if you thought you owned a genuinely diversified global fund, you probably didn't expect your returns to depend so heavily on the share price of a handful of US tech companies. The risk isn't that these companies are bad investments, it's that your portfolio is less diversified than you think.

Is this necessarily a bad thing?

Not automatically. The Magnificent Seven are genuinely profitable, globally dominant companies with strong earnings. They've earned their market position through real business performance, not just hype. If they continue to dominate their markets, a heavy weighting to them will continue to serve investors well.

The risk is twofold. First, their current valuations assume they keep growing fast. If earnings slow, their share prices could fall sharply and take index funds down with them. Second, historical market leaders rarely stay leaders forever. The top seven companies by market cap in 2000 (Microsoft, GE, Cisco, Walmart, Exxon, Intel, NTT) looked invincible at the time. Only one remains in the top seven today.

How can you reduce this concentration if you want to?

Several ways. First, you can add an equal-weight global tracker to your portfolio, which gives every company the same weight regardless of size. This reduces the dominance of the largest companies. Second, you can hold a specific "ex-US" or "ex-Magnificent-Seven" fund alongside your main global tracker to tilt away from the biggest names.

Third, you can allocate a portion of your portfolio to emerging markets, European, UK or Japanese equities to rebalance away from the US. Fourth, some investors add small-cap or value-focused funds, which are typically underrepresented in standard cap-weighted trackers.

Should you rebalance out of global trackers entirely?

Probably not. Standard cap-weighted global trackers are still one of the simplest, lowest-cost ways to invest long-term, and the diversification across thousands of companies is real even with US concentration. The question is whether you want to accept the current concentration or actively tilt away from it.

A reasonable compromise is to keep a global tracker as your core holding (say 70-80% of your equity exposure) while adding a smaller allocation to regions or strategies that rebalance away from US mega-caps. This preserves the simplicity of index investing while reducing single-country, single-sector risk.

Where Mona Fits

Mona's Stocks and Shares ISA gives you access to diversified global investing with a clear view of what you actually own. Transparency about concentration (which companies, which countries, which sectors) matters more as markets become more top-heavy. Mona helps you build a long-term portfolio while staying aware of the structural risks inside seemingly "passive" funds, so you're not surprised by how it behaves when markets move.

The Bottom Line

A typical global tracker is around 70% US equities and 20-25% concentrated in seven US technology companies. This isn't automatically bad, but it's more concentrated than most investors realise. If the Magnificent Seven stumble, your "global" portfolio stumbles with them. Options for reducing concentration include equal-weight trackers, ex-US funds and regional diversification. Most investors are fine keeping a global tracker as a core holding, but understanding what's actually inside it matters more as market concentration grows.

Know what's really in your portfolio. Start investing with transparency through Mona today.

For impartial information and guidance on investing, visit MoneyHelper.org.uk.

Join Mona’s early access waitlist

Join the waitlist

All articles