Is the US Stock Market Overvalued? A 3-Pillar Framework for Australian Investors

Table of Contents

Through 2026, one of the most popular questions hitting our desk has been: should I be investing more in the US stock market? The S&P 500 and Nasdaq have been trading near record highs, fuelled by the ‘Magnificent Seven’ tech companies, and many clients want to know whether the run can keep going.

Rather than offer a yes or no view, we find it more useful to walk through the three pillars holding US valuations up, and what each one really tells you.

The starting point: expensive on almost every measure

The Wall Street Journal piece by James Mackintosh in December 2024 captures the picture well. Stocks are super expensive on just about every measure. That historically has meant low returns in the long run, although the link between today’s valuation and next year’s return has always been weak.

It is worth noting that the recent rally has not been universal. Gains have been fairly narrow, with two-thirds of stocks and 7 out of 11 sectors underperforming the S&P 500 over the period. The headline index is being carried by a small number of very large companies, not by the broad market.

So the question is not really ‘is the US expensive?’ It clearly is. The more useful question is ‘what would have to be true for these prices to make sense?’ Three pillars do most of the work.

Pillar 1: Artificial intelligence

The first and largest pillar is AI. Investors are betting heavily on AI’s transformative potential, but its future impact and profitability are still uncertain. As Peter Berezin, Chief Global Strategist at BCA Research, who holds a bearish view on stocks, notes: ‘Investors are assuming all this capital spending will be worthwhile.’

That is the crux. Either the spending pays off, or it does not. As Mackintosh’s article warns: ‘Either this spending will produce useful products, in which case there will be lots of competing AI models, and the monopoly-like profit margins investors anticipate won’t be possible. Or it won’t, in which case most of it will have to be written off.’

Both outcomes are uncomfortable for today’s valuations. The first dilutes margins. The second produces large writedowns. The sweet middle path, where one or two players capture monopoly-style economics for many years, is a much narrower window than current pricing implies.

Pillar 2: Earnings growth

The second pillar is recent earnings growth. As the article notes: ‘It’s not like we have some bubblelike behaviour where the valuations of everything have gone up, it’s been essentially backed by earnings.’

This is a fair point and worth weighing. Recent robust earnings genuinely do support some of the move higher. Companies are growing, not just being repriced.

The caution is that similar earnings strength was a feature of the late dot-com era too. Earnings can be strong right up to the point where they are not, and high valuations leave little margin for error if growth slows or competition compresses margins. Earnings growth justifies some, not all, of where the market currently sits.

Pillar 3: American exceptionalism

The third pillar is harder to measure but possibly the most powerful: a belief in the structural superiority of the US economy and its tech giants. That belief has attracted enormous global investment into US assets and pushed US valuations to near their highest relative to the rest of the world in decades.

Mackintosh draws a useful parallel: ‘The angst in Europe about American innovativeness mirrors the fear in Washington about Japan conquering electronics and cars in the 1980s. The U.S. might keep its lead in innovation, but there is a risk of repeating the overconfidence that doomed investors in Japan and Nokia to decades of losses.’

In other words, today’s premium may already be priced in. The risk is not that the US loses its edge entirely, it is that the gap between perception and reality narrows over time, which is enough to disappoint expensive prices.

What it means for Australian investors

A few practical takeaways for portfolios with US exposure, whether via direct ETFs, managed funds, or global super options.

• Long-term forecasts from these starting points are typically more modest. That does not mean negative, just less generous than the past decade.
• Short-term forecasts remain optimistic in many places. The market may still move higher in the coming year. Both can be true at the same time.
• Narrow leadership matters. If most of the index’s gains come from a handful of stocks, your real exposure to the ‘US market’ may be more concentrated than you think.
• Diversification across asset classes plays a bigger role here, not a smaller one. The point is to smooth out volatility over the coming years, not to time the top.
• Risk tolerance and horizon matter. Short-horizon investors may find opportunities in the current market, while long-horizon investors might consider diversifying into less expensive assets or adopting a more cautious approach.

The overall takeaway

The US stock market is navigating uncharted territory. Valuations are near record levels, fuelled by tech dominance and the promise of AI. Short-term prospects appear positive in many models, while long-term sustainability is genuinely uncertain. That mix is what creates the apprehension you read about in markets coverage.

For Australian investors, the question is not ‘in or out of the US?’ It is ‘is my US exposure sized in line with my horizon, risk tolerance and overall plan, and is it diversified enough to survive the scenario where one or more of those three pillars disappoints?’ Reasonable people will land in different places on that question. The point is to ask it deliberately, not to drift into a heavy US weighting because it has worked for a while.

How Satori Advisory works

At Satori Advisory we energise every part of your financial world. We integrate your tax, business, wealth and lending as a prosperity engine, aligned with what matters most to you. With a clear roadmap, informed by data and backed by decades of strategic experience, we simplify the complex. We do not offer pre-packaged solutions. We deliver tailored, end-to-end advice that reflects your reality and ambitions. You work directly with senior advisers who listen deeply, think boldly and act with purpose, supported by our trusted team and curated network of financial and business specialists, so you can realise your potential, powered by numbers.

Frequently asked questions

Ready to talk?

If you would like a calm, no-pressure conversation about how your US share market exposure fits into your overall wealth, super and tax plan, we would be glad to set one up.

Please feel free to get in touch on 1300 925 081 or send an email to [email protected] if you’d like to book in a chat on the above or on other matters.