The Availability Heuristic, Hormuz, and Why Clients Are Overweighting the Worst Case

Retail investors tracking volatile markets at home face the same cognitive pressures that behavioral finance research has documented for decades: vivid recent events distort probability estimates. Photo: iStock.

Behavioural

The Availability Heuristic, Hormuz, and Why Clients Are Overweighting the Worst Case

May 8, 2026 7 min The Behavioural Desk

The Brief

The availability heuristic, identified by Kahneman and Tversky in 1973, causes investors to assess the probability of an outcome based on how easily examples come to mind, overweighting vivid and recent experiences.
The Hormuz crisis is providing exactly the conditions under which this bias is most active: dramatic imagery, continuous news cycles, personal experience of higher gas prices, and a compounding series of alarming updates since late February.
Clients are likely overestimating the probability of a permanent supply disruption relative to the historical base rate, which shows that every prior Hormuz closure or near-closure has ultimately resolved.
The April jobs miss adds loss aversion to the availability heuristic, a combination documented in prospect theory: investors feel the pain of job losses disproportionately relative to the counterbalancing gains in gold and technology names from the same market session.
The advisor's role is to restore base rate thinking without dismissing real risks, a distinction that separates genuine de-biasing from unhelpful reassurance.

Every major geopolitical shock creates the conditions for the availability heuristic to dominate investor decision-making. The availability heuristic, which Daniel Kahneman and Amos Tversky first systematically described in their 1973 paper "Availability: A Heuristic for Judging Frequency and Probability," is the cognitive pattern by which people estimate the likelihood of an event based on how readily examples come to mind. Memorable, vivid, emotionally charged events are recalled easily, and easy recall inflates perceived probability.

The Hormuz crisis since late February 2026 has delivered all of the inputs that activate this bias most powerfully. Dramatic news footage of naval confrontations. Daily gas price alerts showing 30% increases at the pump since March. The IEA characterizing the situation as the greatest global energy security challenge in its history. And, as of this morning, the personal economic signal of 18,000 Canadians losing jobs in a single month. Each individual piece of information is accurate. The aggregation of these vivid inputs into a probability estimate for the most catastrophic scenario is where the bias operates.

Why Historical Base Rates Matter Here

The availability heuristic's distortion is clearest when it is set against the historical base rate. The Strait of Hormuz has faced major disruption threats in 1973, during the 1980 to 1988 Iran-Iraq War, during the 1987 to 1988 Operation Earnest Will, in 2011 to 2012, and in the June 2025 preliminary conflict. In each case, global shipping found partial accommodations, alternative routes were developed, and oil prices that spiked on the disruption eventually retraced as markets stabilized or the geopolitical situation resolved. The current disruption is the most severe in the series. It is not categorically different from the historical pattern.

Gerd Gigerenzer at the Max Planck Institute has documented extensively that people's estimates of event probability spike dramatically immediately following vivid related events and normalize over time. The post-event period, which the Hormuz crisis has produced continuously since February, extends the window of peak bias. Investors making rebalancing decisions about their energy exposure right now are making those decisions at a moment when their probability estimates for the worst-case scenario are at their most distorted.

The Compound Effect of the Jobs Data

This morning's Labour Force Survey adds a second cognitive layer. Kahneman and Tversky's prospect theory, formalized in their 1979 paper, established that losses feel roughly twice as powerful as equivalent gains. The April jobs miss of 18,000 will register psychologically as a significant negative event for clients who are already in an availability heuristic-amplified anxiety state. The counterbalancing gains from the same market session, Agnico Eagle and Barrick up more than 3%, Shopify recovering 5.8%, Wheaton Precious Metals reporting record earnings, will receive less psychological weight despite being genuine positive data points.

The compounding of availability heuristic activation with loss aversion is the most dangerous behavioral combination for portfolio decision quality. It is the pattern Terrance Odean documented in his 1998 research on individual investor trading: investors who are most active during periods of market stress consistently underperform relative to those who hold. The cost of acting on the bias is not hypothetical. It is the return gap between the median active response and the passive baseline.

Restoring Base Rate Thinking Without Dismissing Real Risk

The distinction between de-biasing and reassurance is the technical challenge for advisors in this environment. Reassurance, telling clients that everything will be fine, does not address the availability heuristic. It provides a competing narrative that the client can discount as advisor optimism. De-biasing requires surfacing the base rate explicitly: how many prior Hormuz disruptions resulted in permanent structural damage to the global oil market? What does the current diplomatic progress, including the MOU framework being negotiated this week, suggest about the trajectory?

This framing, consistent with Richard Thaler and Cass Sunstein's nudge architecture, does not require the client to abandon their concern. It requires them to hold their concern alongside the historical base rate and make a decision that reflects both, rather than only the vivid recent experience. That is the advisor's technical contribution during a period of heightened behavioral activation: not to be more optimistic than the situation warrants, but to provide the base rate context that human cognitive architecture systematically fails to generate on its own.

Sources

Kahneman D and Tversky A Availability A Heuristic for Judging Frequency and Probability Cognitive Psychology 1973. Kahneman D and Tversky A Prospect Theory An Analysis of Decision Under Risk Econometrica 1979. Odean T Are Investors Reluctant to Realize Their Losses Journal of Finance 1998. Gigerenzer G Reckoning With Risk 2002. Thaler R and Sunstein C Nudge 2008. Wikipedia 2026 Iran war fuel crisis (May 2026). Statistics Canada Labour Force Survey April 2026 (May 8 2026).

Educational content only. This article is published for informational and professional development purposes. It does not constitute investment advice, financial planning advice, or a recommendation to buy or sell any security. Canadian advisors should apply their own professional judgment. Full disclaimer.

Advisor Toolkits — May 8, 2026

🛡️ Respond ▼

What They're Feeling

Clients are experiencing a cascade of availability heuristic triggers: vivid news imagery, personal gas price experience, and now a domestic jobs miss that feels close to home. Underneath the anxiety is a specific fear that the energy situation is categorically different this time and that normal recovery patterns will not apply. This is not irrationality. It is the predictable output of how human memory and probability estimation interact. The advisor who understands this can validate the concern while redirecting the decision.

What to Say

I want to share something about how the current environment is affecting decision-making, because I think it's useful context. The Hormuz situation has been producing exactly the conditions under which people tend to overestimate the probability of the worst outcome: vivid images, daily bad news, and now the jobs number this morning. There is a well-documented pattern in behavioral finance where the easier it is to bring an example to mind, the more likely we think it is to happen. The research shows this consistently leads people to overestimate crisis duration and severity. I'm not telling you the situation isn't serious. It is. What I'm saying is that the historical base rate for Hormuz disruptions resolving over a period of months is strong, and I want to make sure we're making decisions based on that base rate alongside today's headlines, not just on today's headlines alone. What specifically are you most worried about right now?

Who's Affected

High behavioral risk: Clients who have called or emailed more than once this week about the same concern. Repeated engagement with the same anxiety is a sign of availability heuristic activation and escalating loss aversion.

Medium behavioral risk: Clients nearing retirement with heightened sensitivity to sequence-of-returns risk. Their concern has a legitimate structural basis, which makes it harder to distinguish from pure availability bias.

Lower but present risk: Younger clients who have not experienced a major geopolitical market shock before. This is their first Hormuz event. The historical context the advisor provides is genuinely new information for this cohort.

Action Checklist

For clients who have been in frequent contact this week, schedule a structured 30-minute call rather than continuing to respond to individual messages. Fragmented reassurance compounds the anxiety cycle.

Prepare a brief written note on historical Hormuz disruption episodes and their duration, to share in client conversations as a base rate anchor.

Review your most anxiety-prone client list and make proactive outreach calls before the weekend. Clients who hear from their advisor before they call are less likely to make reactive decisions over the weekend.

Document the specific concerns clients raise and the specific responses given, to support a consistent follow-up narrative as the situation evolves.

Follow-Up Email Template

Subject: Putting this week in context

Hi [Client Name],

Thank you for reaching out this week. The news has been genuinely unsettling: the jobs number, the energy situation, and the uncertainty around the Hormuz negotiations are real and I understand why they're on your mind.

One thing I find useful in moments like this is to look at the historical pattern. Every major Hormuz disruption in the past 50 years has ultimately resolved. The current one is the most severe, but the diplomatic progress this week, including a framework deal that appears to be close, suggests the trajectory is toward resolution rather than permanence.

Your portfolio is positioned for uncertainty, not for a specific prediction. I'm comfortable with where we stand. Let's talk early next week if you'd like to go through the specifics.

[Your Name]

This communication is for educational purposes only and does not constitute personalized investment advice.

🎯 Prospect ▼

Client Profiles to Target

DIY investors following the news obsessively: Self-directed investors without an advisory relationship are absorbing every Hormuz and jobs headline directly, with no professional framework to filter it. The availability heuristic is operating at maximum strength in this cohort.

Recently retired investors in the sequence-of-returns window: Clients who retired in the past two years and are in the most vulnerable phase of drawdown have legitimate structural concern alongside the behavioral bias. They need both de-biasing and a concrete portfolio resilience review.

Clients of advisors who are not communicating proactively: An advisor who has not reached out during a period of sustained geopolitical and market stress is implicitly activating their clients' worst-case thinking. The absence of communication is itself a behavioral cue.

Opening Line

I'm calling because the past few weeks have produced exactly the conditions under which people tend to make their worst financial decisions, and I wanted to make sure you had someone to talk to about it before the weekend. You've been following the news. I want to give you the context that most of the coverage isn't providing.

Value Proposition

The behavioral finance research is unambiguous: investors who act during periods of high availability heuristic activation and loss aversion consistently underperform those who do not. The advisor who can identify that pattern in a client, name it clearly, and redirect the decision to a historical base rate framework is providing a specific and measurable service. In this environment, that service is worth more than any market forecast.

Discovery Questions

How much time are you spending following the Hormuz news on a daily basis, and how is it affecting how you feel about your portfolio?

When you think about the worst-case scenario for your investments right now, what does that look like specifically?

Have you made any changes to your portfolio since the Hormuz situation began, and if so, what was the thinking behind those changes?

Is there someone you talk to regularly about your investment decisions, or are you working through this on your own?

Prospecting Email Template

Subject: The Hormuz headlines and investment decisions: a framework

Hi [First Name],

The behavioral finance research is clear: the conditions of the past two months, vivid crisis imagery, personal gas price experience, a jobs miss this morning, are exactly when investors make decisions they later regret. Not because the risks are not real, but because the way our minds process vivid recent events causes us to systematically overestimate the probability of the worst outcome.

I work with clients to identify when that pattern is at work and redirect decisions toward a historical base rate framework. If you're finding the current environment difficult to navigate on your own, I'd welcome a conversation before the weekend.

[Your Name]

This communication is for educational purposes only and does not constitute personalized investment advice.