Citadel Securities thinks investors are sleeping on what could be one of the biggest macro catalysts of 2026: a fast reopening of the Strait of Hormuz.

Frank Flight, a strategist at the market-making giant, said on May 28 that financial markets are meaningfully underestimating the probability of a quick diplomatic resolution between the US and Iran. If he’s right, the mispricing creates an asymmetric setup for traders willing to bet on de-escalation.

The case for a faster reopening

The Strait of Hormuz isn’t just any shipping lane. Roughly one-fifth of the world’s daily oil supply passes through the narrow waterway between Iran and Oman.

Flight’s argument rests on what he sees as accelerating diplomatic activity between Washington and Tehran. A Nikkei report from May 25 added fuel to the thesis, suggesting Iran could reopen the strait approximately 30 days after reaching a deal with the US. That timeline includes mine clearance operations, which is the main logistical bottleneck.

This isn’t the first time Citadel Securities has made this call. Back on April 4, the firm published a note titled “A Route to Resolution” that argued markets were overweighting the chances of military intervention. At the time, Polymarket odds showed an 80% expectation for a ground invasion. Citadel’s view was that negotiation was the more likely outcome, and that the market was mispricing it badly.

That earlier note aged well. Following a US-Iran ceasefire in April, the Nasdaq 100 rallied 13%.

Why the market keeps getting this wrong

The 80% Polymarket odds for military action back in April tell the story. When the dominant story is escalation, that’s where the money flows, even if the underlying probability distribution looks different.

Citadel’s edge, if it has one, may simply be taking the diplomatic signals at face value rather than discounting them. Flight pointed to heightened diplomatic activity as the key indicator, not satellite imagery of troop movements or naval deployments.

What a reopening means for markets

The first-order effect is straightforward: oil prices come down. The Strait of Hormuz closure has been a persistent supply constraint, keeping energy costs elevated and feeding through to headline inflation numbers. Restoring normal shipping through the passage would relieve that pressure relatively quickly.

The April precedent is instructive. A 13% rally in the Nasdaq 100 following the ceasefire suggests that markets have significant upside when geopolitical risk premiums unwind. A confirmed deal with a concrete timeline for reopening could deliver another leg higher.

But Flight’s point isn’t that a deal is guaranteed. It’s that the probability is higher than what markets are pricing. If he’s right that the gap between perceived and actual odds is wide, the expected value of positioning for reopening is positive even accounting for the downside scenario.

Investors watching this space should pay close attention to any formal negotiation timelines, statements from the State Department or Iranian foreign ministry, and movement on mine clearance logistics. The 30-day reopening window reported by Nikkei is the number to track.