The hidden concentration behind many funds and ETFs
Many funds, ETFs, and indices appear to offer distinct exposures, but in practice, a significant portion of them remains dependent on the same core group of companies.
At first glance, many portfolios appear properly diversified.
Investors see different funds, various ETFs, distinct indices, and, ostensibly, a broad structure that conveys a sense of balance. However, that perception does not always align with reality.
Having multiple vehicles does not necessarily mean having multiple independent sources of performance. This is one of the most common misinterpretations in today's market.
Different products do not always mean different exposures
In recent years, the growth of index investing and global funds has significantly facilitated access to international markets. Today, it is common to find portfolios composed of:
- A global fund,
- an S&P 500 ETF,
- a technology index,
- a US growth fund,
- and even other thematic products tied to innovation or artificial intelligence.
On paper, it looks like a multi-component portfolio. The problem arises when analyzing what actually lies within those components.
In many cases, the top holdings repeat themselves time and again: Microsoft, Apple, NVIDIA, Amazon, Alphabet, Meta Platforms… In other words, even if an investor sees different fund names or distinct issuers, a very significant portion of their wealth remains dependent on the same core group of companies. Only the packaging changes.
The market's false breadth
Major US indices have undergone a progressive concentration process in which a few technology megacaps have come to represent a disproportionate weight within the whole.
To assess the composition of the S&P 500, it is advisable to review the index’s composition and weightings as of a specific date, as well as the holdings of each fund. Weightings change and should not be extrapolated without verification.
Many funds that seemingly invest in broad universes ultimately move, in practice, under the influence of these same leading companies. As a result, a global fund, a US ETF, and a technology product can create a sense of variety that does not always translate into genuine diversification in the sources of return.
This concentration is also a form of risk
Concentration is not always apparent while the market is rising. In fact, during bull markets, it often breeds a deceptive sense of security: everything seems to be working, indices hit all-time highs, and portfolios perform positively.
However, if a large portion of wealth depends on a very small number of assets continuing to sustain the market, the actual number of things that must go right is drastically reduced, and the smaller that number is, the greater the structural fragility.
A widespread system-wide collapse is not required for problems to surface; it is enough for the core concentration of weight to:
- Cease growing at the expected pace,
- undergo a valuation correction,
- or lose its capacity to pull the broader index along.
At that point, many portfolios that appeared to be built on distinct foundations discover they were all supported by the very same pillar.
The current context makes this analysis even more relevant
This perspective becomes even more critical in an environment like today's, because while Wall Street continues to demonstrate strength, the macroeconomic landscape continues to accumulate points of tension:
- Persistent international energy conflicts,
- pressure on industrial costs,
- monetary interventions to support currencies,
- and growing uncertainties across specific financial segments.
Despite this, capital continues to seek shelter en masse within the leading US market names, sustaining a perception of stability while reinforcing reliance on these identical assets.
The question, therefore, is not merely whether the indices will continue to rise. The question is how much global wealth requires these exact same names to keep rising in order to sustain that peace of mind.
Looking inside the portfolio, not just at its surface
This is one of the most critical considerations in disciplined wealth planning: analyzing not just how many products a portfolio holds, but what underlying drivers are actually sustaining its performance.
True diversification is not measured by the number of funds held. It is measured by the degree of independence between the underlying drivers of wealth.
Two portfolios can each hold five products, yet one may be far more concentrated than the other. The distinction does not lie in the quantity of holdings; it lies in the structural quality of the portfolio.
The question every investor should ask
Beyond the number of funds, ETFs, or indices in a portfolio, the core question is: how many specific assets does the ongoing, normal performance of this wealth truly depend on?
Because the perception of diversification is often present. What is not always present is genuinely distributed protection.
Sources and Further Reading
Informational content provided by SR Nexus. This does not replace official product documentation or an individual assessment of personal circumstances. Editorial update: November 10, 2026.
