Increasing Concentration of Technology Stocks Heightens Risk for Global Equity Portfolios

Concentration risk arises when a limited group of sectors or common earnings drivers disproportionately influences a portfolio's performance. Within the ACWI, significant players like Nvidia, Apple, and Microsoft belong to IT; Alphabet and Meta fall under communication services; and Amazon is categorized as consumer discretionary. Despite appearing to diversify across multiple sectors, investors may remain heavily exposed to the same technological trends, particularly related to artificial intelligence (AI).

The interdependence of earnings across differently classified technological firms raises concerns among investors, as a global fund, even one with thousands of securities, may still heavily depend on a few key U.S. companies and the semiconductor supply chain. While this concentration does not predict an immediate downturn, a letdown in AI-related spending could simultaneously impact various market segments and their lenders.

Ashley Lester, MSCI’s chief research and development officer, noted in January that about 40 percent of the U.S. equity market is concentrated in the top 10 stocks, almost all of which are technology-related. Thus, perspectives on the U.S. economy become closely tied to assumptions about AI, as there is limited exposure to AI investments outside the U.S. This observation highlights four overlapping risks in global portfolios: exposure to a small number of companies, reliance on the technology sector, dependency on the U.S. market, and close ties to AI.

Market capitalization weighting has fueled this trend, where a company’s weight in an index grows as its stock value increases relative to peers. While beneficial for index funds, this practice elevates investors' exposure to companies that have already experienced substantial price increases.

The rise of index investing has further magnified these weights across retirement accounts and institutional portfolios. As of July 2026, 64.1 percent of assets within U.S. equity mutual funds and ETFs were held in index-tracking products, while index funds accounted for 19 percent of the overall U.S. stock market at the end of 2025.

Investors aiming to manage this concentration risk could consider strategies like equal-weighted indices, value investing, or exposure to smaller companies. However, these strategies also carry inherent risks and may result in underperformance, especially as current market leaders persist in their success,

The MSCI ACWI Information Technology Index illustrates how a setback in AI could affect technology stocks globally. Though the index has 326 securities, the top ten represented 64.47 percent of the total market-capitalization weighting as of late August, concentrated significantly in semiconductors and U.S. firms. If AI adoption falls short of expectations, reduced spending on critical assets like chips and data infrastructure could lead to widespread earnings declines among connected industries.

J.P. Morgan Asset Management forecasts that major players such as Alphabet, Amazon, Meta, Microsoft, and Oracle will invest around $697 billion in capital expenditures during 2026, with their AI investments projected to rise from 33 percent of operating cash flow in 2023 to an estimated 93 percent in 2026. This growing reliance on AI infrastructure highlights its critical importance to the earnings of businesses involved in the broader supply chain.

As AI investments increasingly hinge on borrowing, the implications extend beyond equity markets; losses from underperforming AI could ripple across bondholders and private credit funds. According to the Bank for International Settlements, outstanding loans to AI-related sectors surged from negligible levels in 2015 to over $200 billion by 2025, reflecting a growing trend.

Ultimately, investors face the challenge of reducing reliance on large technology firms while considering the performance trade-offs associated with diversifying their portfolios.