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May 2026

Why This Oil Shock May Be Different

Portfolio Manager

Oil markets have endured many shocks over the past half-century. Embargoes, revolutions,wars, and high-stakes geopolitical negotiations have all driven sharp price moves and unsettling headlines. This has left us asking the age-old question: Is this time different? In our view, what distinguishes the current episode is not simply the degree of volatility, but the
nature of the disruption itself.

For the first time in modern history, the Strait of Hormuz – the most critical artery in the global energy system – has been effectively taken offline at scale. Not legally closed, but operationally disabled in a way markets have never previously had to price.

How Past Oil Shocks Differed

Historically, oil shocks have originated from upstream supply decisions or production failures, not from the breakdown of the transport mechanism that connects producers to the world. A look back on previous oil crises illustrates this:

  • 1973–74: Arab Oil Embargo: This shock was more political in nature. Exporting nations chose to restrict supply in response to geopolitical events, but oil continued to flow through Hormuz. The constraint was imposed at the source, removing roughly 7% of global supply, significant, but operationally contained.
  • 1978–79: Iranian Revolution: Supply fell sharply as Iranian production collapsed amid domestic upheaval. Prices surged, and inflation followed, but once again the Strait remained open. This was a production shock, caused by a political incident, not a chokepoint failure.
  • 1980s: The Iran–Iraq “Tanker War”: This episode is the closest historical parallel to the present situation. Tankers were attacked, mines were laid, and insurance costs rose sharply. Yet shipping continued, often under naval escort, most notably during the US-led Operation Earnest Will. While the strait was dangerous, it was never completely shuttered.
  • 1990–91: Gulf War: Iraqi exports were removed almost overnight. Prices surged, but other Gulf producers responded by increasing output and spare capacity absorbed much of the shock. Throughout the conflict, Hormuz remained functional, and the system adjusted and absorbed the supply change.
  • Post-2000 Threats (2008, 2012, 2019): Since the turn of the century, there have been several threats from Iran to close the strait; however, none led to any prolonged or meaningful impact. Markets repriced risk briefly, oil spiked, and each time shipping continued, and the threat faded without incident.

Across all these episodes, one feature was constant: the plumbing of the global oil market kept working.

What Could Make This Episode Different

The current disruption represents a potential structural break rather than a replay of familiar history. For the first time, the Strait of Hormuz has been functionally removed from service even if no formal closure has been declared.

Tanker traffic has all but come to a standstill:

Commercial shipping through the strait has slowed to a trickle as insurers withdraw cover, shipowners refuse transit, and crews invoke war risk clauses. In practical terms, this is equivalent to closure for much of the market. In previous crises, tankers sailed, sometimes nervously or sometimes under escort. As of today, most simply choose not to set sail at all.

The scale of supply at risk is unprecedented:

Approximately 20% of global oil supply, along with a material share of liquid natural gas (LNG) exports, normally transits Hormuz. That is more than double the scale of any prior oil shock. Independent research groups have characterised this as the largest oil supply disruption on record, not because every barrel has disappeared, but because access to them has been simultaneously lost.

There is no meaningful spare capacity buffer:

In prior shocks, spare capacity elsewhere in the system helped stabilise markets. Today, spare capacity is limited and largely stranded behind the same bottleneck. Producers willing and able to increase output cannot easily move barrels if tankers cannot transit. This materially reduces the market’s ability to self-correct.

The bottleneck itself is the target:

Previous shocks removed supply by damaging fields, toppling governments, or imposing embargoes. This one disables the artery, not just the organ. Energy systems can often absorb the loss of a producer. They struggle far more when the transport mechanism fails. Disabling Hormuz affects the entire Gulf simultaneously.

The risk is systemic, not cyclical:

The International Energy Agency (IEA) and other leading energy bodies have described this scenario as a systemic risk to the global energy system. Once a chokepoint is shown to be vulnerable, the risk does not simply evaporate when political rhetoric softens, or ceasefire discussions begin. Insurance costs, shipping behaviour, and risk premia tend to reprice
permanently. The genie does not go neatly back into the bottle.

Why Markets Are Struggling to Price It

Equity markets are well-practised at absorbing policy shocks. They are far less comfortable with physical constraints.

The sharp oscillations in oil prices, spiking on disruption headlines and retreating on hopeful commentary, suggest investors remain anchored to historical playbooks that assume oil shocks are temporary, political, and ultimately reversible. This one may not be. That does not mean alarm is warranted. It does mean that complacency could be misplaced.

What We Are Watching

Our focus remains on signals rather than headlines. With no shortage of noise present, the signals that matter the most are:

  • Physical shipping data: Evidence that insurers, shipowners, and crews are genuinely willing to resume large-scale transit through the Strait of Hormuz.
  • Inventory drawdowns: The pace at which global oil and refined product stocks are depleted if disruption persists.
  • Policy responses: Coordinated releases from strategic reserves and the limits of their effectiveness where transport constraints remain unresolved.
  • Second-round effects: How higher energy costs feed into inflation, consumer confidence, and ultimately earnings expectations.
  • Market behaviour: Whether risk assets continue to treat this as a temporary scare or begin pricing a more persistent energy shock.

Periods like this are uncomfortable by design.

They force repricing, challenge assumptions, and test portfolio discipline. They also tend to create opportunities for investors willing to separate genuine volatility from permanent impairment.

Markets have navigated oil scares before. What they have not navigated is a sustained, large scale disruption to the world’s most important energy chokepoint. That difference deserves attention – not fear, but a level of respect.