When Fund Flows Become a Warning Sign

There is nothing wrong with owning the US equity market. The US remains home to many of the world’s strongest companies, most profitable technology franchises and deepest capital markets.

But there is a difference between owning the US as part of a disciplined global portfolio and chasing the US because everyone else is doing the same thing.

Recent fund-flow data should give investors pause.

In June, US equity funds experienced a sharp swing in investor behaviour. LSEG Lipper data showed that investors added $37.63bn to US equity funds in one week, only to withdraw $3.53bn the following week. The reversal was even more extreme in technology funds, where $21.46bn of inflows were followed by almost $20bn of outflows.

That is not the behaviour of patient, valuation-sensitive capital. It looks much more like investors chasing recent performance, then rapidly de-risking when doubts emerge.

This matters because flows are not just numbers. They are evidence of behaviour.

At market lows, investors often withdraw money after the pain has already been felt. At market highs, they often add money after the gains have already been made. That does not mean every inflow marks a top, but it does mean large, concentrated and performance-chasing flows should be treated with caution.

The current US equity rally has clear fundamental support. Artificial intelligence is driving real investment. Earnings from parts of the technology sector remain powerful. The US economy has continued to show resilience. None of this should be dismissed.

However, strong fundamentals do not remove valuation risk. They often create it.

Vanguard’s latest capital markets work noted that US equities remained stretched, with the cyclically adjusted price/earnings ratio still well above fair value. It also noted that ex-US equities remained more attractively valued relative to the US market.

That is the key point. Investors may be right that the US contains many of the best companies in the world. But the price paid for those companies still matters.

The concentration risk is equally important. S&P Dow Jones Indices has noted that the ten largest companies in the S&P 500 represented almost 40% of the index by mid-2025, a level of concentration not seen since the mid-1960s.

This creates a behavioural trap. Investors think they are buying broad market exposure, but in practice a growing share of their return is being driven by a narrow group of mega-cap companies. The portfolio may look diversified by name count, but the outcome is increasingly dependent on a small number of businesses and one dominant investment theme.

There are also signs that the crowd is not only buying the same market, but in some cases doing so with increasing leverage. Reuters recently reported that assets in US-domiciled leveraged exchange-traded products had doubled in recent months to around $200bn.

Primary dealers’ equity repo exposure has surpassed $220bn, while only one of the 11 S&P 500 sectors — Information Technology — had outperformed the broader index over the previous three months.

That combination should make investors uncomfortable: large inflows, narrow leadership, elevated valuations and rising use of leverage.

It does not prove that investors are buying the top. Markets are rarely that simple. The US market could continue rising, particularly if earnings keep surprising positively and AI investment translates into genuine productivity gains.

But it does suggest that the margin for error has narrowed.

When investors crowd into the same area for the same reason, the risk is not simply that the story is wrong. The risk is that the story is already fully reflected in prices. In that environment, even good news may not be enough. A slight disappointment in earnings, margins, interest rates, AI monetisation or capital spending discipline can be enough to trigger a sharp rotation.

That is why chasing the crowd is dangerous. It feels safest at precisely the point where risk may be building.

The most comfortable investment is often the one that has just performed best. The most popular allocation is often the one that has recently looked most obvious. But markets rarely reward investors for simply buying what everyone else already owns.

For MGTS Qualis Funds, the conclusion is not to avoid the US. That would be too simplistic. The US remains an essential part of a global equity allocation.

The conclusion is to avoid becoming hostage to one market, one style, one theme or one narrow group of companies.

We believe portfolios should remain diversified across regions, styles and fund managers. We want exposure to quality businesses and structural growth, but not at any price and not with excessive dependence on the same crowded trade. We also believe that active judgement matters more when markets become concentrated, valuations are stretched and investor behaviour becomes increasingly momentum driven.

US exceptionalism may continue. But investors should be careful when exceptionalism becomes consensus.

The role of fund management is not to follow the crowd. It is to understand where the crowd is, what it is paying, and what risks it may be ignoring.

Past performance is not a reliable indicator of future results. The value of investments can fall as well as rise and investors may get back less than they originally invested.

This article is for information only and does not constitute investment advice or a personal recommendation.