ASX Hits Record Highs as Global FOMO Index Signals Return Risk

Key Takeaways

• Record highs on the ASX may be attracting momentum-driven investors even as sentiment indicators point to crowded optimism.
• Research links a 10% rise in the Global FOMO Index with a 1.7% to 2.0% decline in monthly returns and lower risk-adjusted performance.
• Business leaders and investors may need to distinguish durable earnings growth from valuation gains powered mainly by herd behavior.

The ASX is reaching record territory, but the mood behind the rally may be becoming as important as the prices themselves. The Australian Financial Review has highlighted elevated fear of missing out, or FOMO, as a warning that investor enthusiasm could be getting ahead of underlying business fundamentals.

That does not mean a market reversal is imminent. Sentiment can carry equities higher for longer than cautious investors expect, particularly when benchmark records generate headlines and encourage sidelined capital to return. Still, evidence linking elevated FOMO with weaker subsequent performance gives portfolio managers and corporate decision-makers a reason to examine what is driving current valuations.

The headline finding is uncomfortable. Research published through ScienceDirect in 2025 found that a 10% rise in the Global FOMO Index was associated with a 1.7% to 2.0% decline in monthly stock returns. The index uses Google search activity to capture changes in public attention around FOMO, creating a broader behavioral measure than conventional market surveys.

Investors do not need to believe an asset is cheap when they assume someone else will pay more tomorrow. That dynamic can turn recent gains into their own justification. Rising prices attract attention, attention brings in buyers, and those buyers push prices higher again. Behavioral finance describes this as herd behavior, but in real markets, it often looks less dramatic. It can simply be a portfolio manager reducing cash because peers are outperforming.

The volatility result adds another wrinkle. The same 2025 study associated a 10% increase in the FOMO index with a 2.02% to 2.1% reduction in realized volatility. On the surface, calmer trading might seem reassuring. In practice, lower volatility during a crowded rally can disguise the accumulation of risk rather than show that risk has disappeared.

When investors broadly agree on the direction of the market, day-to-day price movements can remain relatively restrained. The problem emerges when that agreement breaks. A change in earnings expectations, interest-rate assumptions, or economic data can leave too many investors attempting to reduce similar positions at once.

The more consequential measure may be the Sharpe ratio, which compares investment returns with the volatility taken to earn them. The research found a 4% reduction in the Sharpe ratio when FOMO increased, indicating a deterioration in risk-adjusted returns. In plain terms, investors may be receiving less compensation for the risks embedded in elevated prices.

An earlier version of the research available through SSRN places the indicator within a longer-running effort to use online search behavior as a window into investor psychology. Search data is not a valuation model, of course. It does not replace analysis of cash flow, margins, debt, competitive position, or management execution. It can, however, reveal when public attention is becoming unusually concentrated around the anxiety of being left behind.

For technology and business leaders, the signal has implications beyond portfolio allocation. Strong equity markets can affect acquisition appetite, employee compensation, capital raising, and board expectations. Executives may find that projects receive more generous assumptions when investor confidence is high. Large infrastructure proposals such as the Suburban Rail Loop occupy a different investment category, but they illustrate the broader challenge of separating long-duration economic value from the optimism surrounding major commitments.

Technology valuations deserve particular care because credible growth and speculative enthusiasm can coexist. Cloud computing, artificial intelligence, and digital infrastructure continue to support substantial corporate investment. Microsoft’s Azure, for example, topped $100 billion in revenue during the 12 months ended June 30, while its cloud computing division recorded its fastest expansion since early 2022. Those are operating results, not merely a sentiment story. Yet even strong businesses can become vulnerable when prices assume unusually favorable growth far into the future.

That said, FOMO data works more effectively as a risk flag than as a market-timing switch. Investors can respond by stress-testing valuation assumptions, reviewing position concentration, and asking whether expected returns remain attractive under less generous scenarios. The ASX may continue setting records. The more useful question is whether those records are being supported by improving fundamentals, or increasingly by the fear that everyone else has already joined the rally.