How much US exposure is right for you?

By Staci West on 30 June 2026 in US

 As an American living in the UK for over a decade, this week feels like my own version of the Olympics. On one hand, I’m gearing up to celebrate the 4th of July — complete with questionable quantities of food and my annual attempt to convince my British friends to indulge me in America’s birthday… not just any birthday, but its 250th.

On the other hand, my household will be firmly rooting for England this Wednesday in the FIFA World Cup, before I inevitably fall asleep and wake up to the US taking on Bosnia and Herzegovina in the knockout round at 1am. No pressure.

Somewhere between the food prep and fixture stalking, I started thinking about something a little less chaotic: how much US exposure is actually right for your portfolio? Can you have too much of a good thing? Short answer: yes.

What is concentration risk?

No investor can predict which country will perform best over the next decade. No one knows which industries will fall out of favour or which companies will disappoint. If your portfolio depends too heavily on a single answer to any of those questions, you’re taking on concentration risk.

Although concentration risk can show up in lots of ways: too much exposure to one asset class, one sector, one investment style, or one region. Today, let’s focus specifically on the US.

Is your global fund just a US fund?

The US currently makes up roughly three-quarters of the MSCI World Index. That means if you own a passive global tracker, or an actively-managed fund that stays fairly close to the index, a large chunk of your money is already invested in the US. In other words: for every £1 you invest in a typical global fund, around 70–75p may already be in US companies.

And it gets trickier. You might think owning multiple global funds increases diversification. But if all those funds own the same big American names, you may just be stacking similar exposures on top of each other.

For example, if your global fund, technology fund, and dedicated US fund all own Apple. You’ll have accidentally built an Apple fan club.

Why does too much US exposure matter?

To be clear, this isn’t anti-America. I’m American. I love the US. The economy is dynamic, innovative and home to some of the most influential businesses in the world. There are very good reasons US markets have performed so strongly. But strong performance can create blind spots. It can also mean:

1. You may not be as diversified as you think

If most of your portfolio sits in US equities, you’re also heavily exposed to: the US dollar; US interest rates; US economic growth; and US consumer spending.

2. Valuations are high

US equities, especially large technology companies, are expensive by historical standards. Investors are willing to pay a premium because these businesses are seen as reliable growth engines. But expensive assets can produce lower future returns. Think of it like buying a house in the trendiest postcode. It might still be a great house but you’re paying a lot for it. Bottom line: finding bargains gets harder.

3. Leadership changes

Market leadership doesn’t stay the same forever. There have been decades when Japan dominated. Periods when emerging markets led returns. Years when the UK outperformed. The next decade may not look like the last. Yesterday’s winner doesn’t automatically become tomorrow’s winner.

So… how much US is too much?

Annoyingly, there’s no magic number. The “right” amount depends on your goals, time horizon, risk tolerance, and your comfort with concentration. Some investors are happy with market-cap weighting and accept 70%+ US exposure. Others may look to reduce that concentration and aim for something closer to 50% of equity exposure in the US, giving more room to Europe, Asia, emerging markets, and the UK.

Neither approach is automatically right or wrong. The important thing is this: know what you own and why.

Yes, the US deserves a place in most portfolios

But whether you’re cheering for England on Wednesday, the US on Thursday, or simply hoping your household survives mixed sporting loyalties, one thing remains true: Putting all your faith in one team (or one market) is rarely the safest strategy.

For younger investors especially, it can be easy to assume the US market always outperforms. After all, over the past decade, US equities have dominated global markets, driven largely by technology giants. But history tells a more nuanced story.

There have been long periods when the US was deeply out of favour. In the 10 years to June 2006, North America ranked in the fourth quartile of regional performance, returning just 48%, compared with 157% for UK smaller companies and 130% for Europe^.

The lesson? Market leadership changes. Today’s winner is not guaranteed to remain tomorrow’s champion. The US remains an important part of a diversified portfolio, but diversification matters because no single market stays on top forever.

Three ways to play US in your portfolio

1. A global fund that doesn’t bet it all on the US

Ranmore Global Equity is a good example of what true differentiation looks like. This is a global value fund that has proven its ability to perform across a range of market environments, and it looks very different from both the MSCI World Index and many of its peers. The portfolio spans the market-cap spectrum and, notably, the US is only a quarter of the fund’s regional allocation. Asia accounts for 42% of the fund, Europe 24%, and the US just 25%*, offering investors a genuinely broad a global equity allocation.

2. US funds that give access to different parts of the market

Run out of New York, the Schroder US Mid Cap fund focuses on small and medium-sized companies. Although large caps tend to dominate headlines, mid-caps offer a number of attractive characteristics that are often overlooked. Research shows that over the past 30 years, mid-caps generated 11.2% annualised returns, compared with 10.9% for large caps, while maintaining a similar risk-adjusted profile**.

If you want to go even further down the market-cap spectrum, look no further than the Artemis US Smaller Companies fund. While stock selection is paramount on this fund, the overall shape of the fund will reflect the manager’s view of the US economy. Investing mainly in US small-caps, this fund highlights why active management can still add value in the US market. It has not only delivered over 300% for investors over the past 10 years but has also outpaced the S&P 500 over both one and five years***.

3. Avoiding the US and looking further afield

Of course, you might decide you don’t want to add any further US exposure to your portfolio and instead look for complementary funds in Asia or the UK. FSSA Asia Focus is a high-conviction, stock-picking fund investing in Asian companies demonstrating sustainable and predictable growth. The fund currently has 42% in technology and 20% in financials, with geographic exposure across Taiwan, China, South Korea, India and more*.

Further diversification into the UK market might include Liontrust Special Situations, a best-ideas portfolio that invests in UK companies of any size or sector. It currently holds roughly 40% in FTSE 100, 29% in FTSE 250 and 18% in AIM-listed companies*.

^Source: FE Analytics, total returns in pound sterling, 1 June 1996 to 1 June 2006
*Source: fund factsheet, 31 May 2026
**Source: etftrends.com, 21 January 2026
***Source: FE Analytics, total returns in pounds sterling, 29 June 2026