Emerging markets just beat the S&P 500 by 11 points: is your portfolio too American to notice?

Since the start of 2026, the MSCI Emerging Markets Index has climbed about 16%, more than three times the S&P 500’s roughly 5% gain over the same stretch — one of the widest performance gaps between the two in years. Analysts have also been lifting profit forecasts for emerging-market companies by around 30% this year, versus an average 10% upgrade for S&P 500 companies, while EM equities still trade at a 44% discount to US stocks on forward earnings, the widest gap since April 2025. None of that is a reason to chase the rally. It is a reason to ask a duller, more useful question: how much of your equity portfolio is actually outside the US, and did you choose that number on purpose?

What is “home bias,” exactly?

Home bias is the well-documented tendency of investors to hold far more of their home country’s stocks than that country’s actual share of the global market would justify. The US represents roughly 60% of global equity market capitalization in the MSCI All Country World Index — a large share, but still well under two-thirds. Multiple studies of US retail portfolios, gathered by Visual Capitalist, put actual US investor allocations to domestic equities at 70% to over 90%. That gap — a 60%-ish share of the world’s market cap turning into 80%-plus of the average American’s stock holdings — is not a deliberate bet most people made. It is what happens by default when you buy what’s familiar, quoted in your own currency, covered by the news you read.

Isn’t buying the US market basically buying the world anyway?

Not in composition, and — this year — not in return either. The S&P 500 gives you exposure to US-domiciled, US-listed companies, many of which do sell abroad, but the sectors, valuations, and macro sensitivities are still those of one economy and one currency regime. The concentration inside that single index is itself already historically high; layering a second, geographic concentration on top — nearly all your equity risk sitting in one country — compounds the same structural bet: that the market’s current leadership keeps leading. 2026’s emerging-market rally is one live data point showing that bet doesn’t always pay off in the period you’re actually invested through.

Why would owning other countries actually reduce risk?

For the same reason any two assets reduce a portfolio’s risk when combined: not because one is “better,” but because their returns don’t move in lockstep. Country and regional equity markets respond to different central banks, different currencies, different earnings cycles and different politics — correlated to some degree with US equities, but not perfectly. A mean-variance optimizer treats a country or region exactly like it treats any other asset: an expected return, a volatility, and a correlation to everything else you hold, all three of which decide how much adding it improves the portfolio’s risk/return trade-off. A 44% earnings-multiple discount and a 30% forecast upgrade are inputs an optimizer can actually use; “I’ve heard the US always wins long-term” is not.

So should you sell US stocks and buy emerging markets now?

No — and this article isn’t in a position to tell you that, or to tell you what allocation, if any, fits your situation. Chasing a rally that has already run 16% is a different decision than checking whether your baseline exposure was ever deliberate, and the two get confused constantly. What’s verifiable here is narrower: US investors are demonstrably concentrated in US equities well beyond the country’s share of global markets, that concentration has a name and a documented behavioral cause, and 2026 supplied a concrete illustration of the cost it can carry in a given stretch — not proof that it always will.

How do you find out if your own portfolio has this problem?

Not by intuition — by actually adding up what you hold, by domicile, the same way you’d check concentration inside a single index. A portfolio built one ETF or one broker’s “featured picks” at a time accumulates geographic tilt nobody chose on purpose, in exactly the way it accumulates single-stock concentration. Measuring it means looking at where each holding is actually domiciled — not what currency it happens to be quoted in on your brokerage screen — and comparing that split to a deliberate benchmark, whether that’s global market-cap weights or a mix you’ve reasoned through yourself.

What this is NOT

This isn’t a call to rotate out of US equities into emerging markets, or a forecast that the 2026 EM rally continues, reverses, or represents a permanent regime change. The performance and valuation figures cited above are historical data points reported through 2026 — evidence that geographic concentration is a measurable, real exposure, not a prediction about which country wins from here. Past outperformance, in either direction, doesn’t guarantee future outperformance.

The world’s stock market isn’t 80% American. If your portfolio is, that’s not a market view you made — it’s a default nobody double-checked.

Sources: Yahoo Finance, “Emerging Markets Rise 16% in 2026, Outpacing S&P 500 by Wide Margin”; Visual Capitalist, “Charted: How Investors Allocate Their Investments, by Country”.