U.S. stocks have rarely been more dependent on a single idea: that a handful of mega-cap tech companies can keep the market aloft.
As of the end of the third quarter (Q3), the eight largest American companies — all in technology or tech-adjacent industries — represented 36.1% of index value, according to the MSCI USA Index.
That’s a higher concentration than at the peak of the dot-com boom, leaving investors one stumble away from a market-wide setback.
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For globally minded investors, this is more than a warning sign. It’s an opening. Developed markets outside the U.S. offer lower valuations, more balanced sector leadership and less reliance on a few dominant names.
Together, these factors create one of the widest relative opportunity gaps in years.
A market riding on the Magnificent 7
The MSCI EAFE Index, which covers developed markets in Europe, Australasia and the Far East, is far less top-heavy. Its largest holdings span technology, staples, health care, financials and energy, with the top eight stocks accounting for slightly more than 10% of index weight.
According to MSCI, as of September 2025, financials are EAFE’s single largest sector at roughly 25%, while technology represents a more moderate 8%.
In these more balanced markets, global peers — from enterprise software leaders in Europe to consumer tech innovators in Asia — are steadily building their presence, including in parts of the artificial intelligence (AI) value chain.
That structural difference in concentration means international markets are not dependent on the fate of a single sector or a small set of companies.
In the U.S., the opposite is true. Narrow leadership leaves little margin for error, and even a modest pullback in its top names could have an outsize impact.
In early April, the S&P 500 lost $5 trillion in market value in just two trading days, a stark reminder of how quickly concentrated gains can turn from strength to vulnerability.
International markets: Broader, cheaper and higher yielding
The case for looking abroad goes well beyond different names on the roster. International equities offer sector and earnings diversity at valuations that remain compelling.
According to MSCI data, as of the end of Q3, all 11 U.S. sectors traded at more expensive price-to-earnings multiples than their EAFE counterparts. Dividend yields also favor international markets: 2.9% for EAFE vs 1.2% for the U.S.
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Currency trends add another potential tailwind. The first half of 2025 marked the weakest stretch for the U.S. dollar since 1973, driven by uncertainty around U.S. policy direction and rising debt levels.
With growth expectations between the U.S. and other developed economies now closer than they’ve been in years, a softer dollar could further boost returns for U.S.-based investors in non-dollar assets.
Why waiting could cost you
After 15 years of U.S. market dominance, portfolios that haven’t been actively rebalanced might be unintentionally overweight in Big Tech. The question for investors isn’t only if these companies can keep delivering, but whether it’s prudent to keep betting as heavily on them, now that valuations have soared and concentration risk is at historic highs.
Reallocating even a portion of U.S. equity exposure toward developed international markets can help reduce reliance on a narrow group of U.S. mega-caps, capture attractive valuations abroad and position for potential currency-driven tailwinds.
From concentration risk to global opportunity
When one theme dominates market leadership, history shows it rarely lasts. Today’s extreme reliance on the Mag 7 is both the result of extraordinary business performance and a source of systemic vulnerability.
Looking abroad isn’t about diversification for its own sake — it’s about broadening return drivers at a time when U.S. leadership rests on an unusually narrow base.
By acting now, investors can tap into a wider opportunity set, mitigate overconcentration risk and better prepare their portfolios for the next phase of global market leadership.
Views are those of the author as of September 30, 2025, and are subject to change without notice. Information is from sources believed to be reliable, but accuracy is not guaranteed. This is not a recommendation or an offer to buy or sell any security and does not consider individual objectives or circumstances. Past performance is no indication of future results. All investments have the risk of loss.
