US Dominance and New Market Entrants Reshape Vanguard's All-World ETF Landscape

The Vanguard All-World ETF is heavily tilted toward US tech stocks, raising concentration and valuation concerns as FTSE Russell prepares to add Vietnam and Greece in September 2026.

The Vanguard FTSE All-World UCITS ETF presents an increasingly tangled picture. On paper, it offers exposure to 48 countries and more than 4,200 stocks, a proxy for roughly 90% of global equity market capitalisation. In practice, nearly two-thirds of its weight now sits in the United States, and a quarter of the entire index is tied to technology stocks. Yet at the same time, the underlying benchmark is about to undergo its most significant geographic reconfiguration in years.

The ETF closed at €162.64 on Wednesday, a whisker below its 52-week high, and has returned 26.16% over the past twelve months. Over the year to date the gain stands at 11.12%. Inflows have been torrential: the week to 22 May 2026 alone saw €420.5 million pour into the fund, following €685.07 million the prior week. That demand has swelled assets under management to roughly $66bn, up from around €39.1bn earlier in the year.

A concentration headache that keeps growing

The US slice of the FTSE All-World Index has been expanding for decades. In September 1987 it stood at 37%; by September 2025 it had climbed to roughly two-thirds. Japan, once a rival, now commands a tiny fraction. No other single market reaches even 5% of the index weight. FTSE Russell’s own diversification factor—a measure of how many stocks truly drive returns—has collapsed from about 500 in the early 2010s to little more than 100 today.

The top ten holdings account for just under a quarter of the index, even though the full roster includes 4,254 names. Apple, Microsoft and Nvidia dominate, flanked by other US tech heavyweights. The only non-American standout is Taiwan’s TSMC, itself a beneficiary of the artificial-intelligence and semiconductor boom that has reshaped market weights.

This lopsided profile matters more now because non-US markets have recently taken the lead. A weak dollar boosted returns for European and Asian equities in 2025, and that trend has continued into 2026. The US Dollar Index lost nearly 10% through September last year. Against the euro, the dollar shed 13.5%; against the Swiss franc, 13.9%; the yen gained 6.4%, and a basket of emerging-market currencies rose 5.6%. Since the Vanguard ETF does not hedge currency risk, a strengthening euro eats into returns for euro-based investors holding an overwhelmingly US-centric portfolio.

Valuations add another layer of unease. The cyclically adjusted price-to-earnings ratio of the US market sits near 41.6 in 2026, far above the long-term average of 17.3. Only the December 1999 dot-com peak, with a CAPE of 44.19, was higher in more than 140 years of US stock-market history. An investor buying a world ETF today automatically acquires a large slug of that expensive US exposure.

Vietnam and Greece rewrite the index map

Against this backdrop of US hegemony, FTSE Russell is quietly redrawing the index’s geographic boundaries. On 21 September 2026, two countries will change status.

Vietnam will graduate from a frontier market to a secondary emerging market. The upgrade follows regulatory reforms that ease access for foreign investors, notably the removal of a pre-financing requirement for institutional players and the introduction of a formal process for handling failed trades. To avoid market disruption, FTSE Russell is phasing in Vietnamese stocks over four tranches stretching to September 2027. Names likely to enter the index include Hoa Phat Group, Vietcombank, Vingroup and Vinhomes.

Greece will take a more dramatic leap. In a single step on the same September date, the country will return to developed-market status, a designation it lost during the sovereign debt crisis in 2013. The move carries symbolic weight as well as mechanical consequences for index weights. Potential additions include Alpha Bank, Eurobank, National Bank of Greece, Piraeus Bank, OTE, PPC and Allwyn.

For the All-World ETF, these are automatic adjustments. The fund tracks the benchmark without judgment, buying and selling as the index composition shifts. Indonesia, meanwhile, remains in limbo: FTSE Russell has postponed its review, with no changes expected before the same September window at the earliest.

Can algorithms fix the concentration problem?

FTSE Russell is also exploring algorithmic reweighting schemes designed to reduce the index’s extreme tilt toward a handful of large US technology stocks. The goal would be to lower concentration without inflating tracking error to uncomfortable levels. Complementing that, small-cap and completion indices are being considered as building blocks for broader market exposure.

The Vanguard ETF itself continues to operate efficiently. Its total expense ratio remains 0.19% per year, and the fund uses sampling to replicate the benchmark, holding a representative selection rather than every single constituent. It is listed in euros, pounds, dollars and Swiss francs.

What the ETF cannot control is the sheer gravitational pull of the US market. The iShares Core S&P 500 UCITS ETF carries an annualised volatility of 11.58%, and the Vanguard world fund is not far behind—the heavy US weighting narrows the diversification gap between a global portfolio and a purely American one.

For holders of the Vanguard FTSE All-World, 2026 is shaping up as a year of two stories. The first is about US tech supremacy, a weakening dollar and stretched valuations. The second is about index mechanics, frontier markets rising and a benchmark that is slowly, if still incompletely, broadening its horizons. Neither story is resolved, but both are now in play.