Markets Bet Strait of Hormuz Will Stay Closed for Weeks

Prediction markets now give less than a 50% chance that normal shipping will resume through the Strait of Hormuz by June 1 after Iran seized two vessels, state television aired footage of commandos boarding ships, and U.S. forces boarded a tanker in the Indian Ocean.

On Kalshi, traders assign a 42% probability of normal traffic by June 1, rising to 59% by July 1 and 61% by Aug. 1. Polymarket shows a 45% chance by the end of May and a 67% chance by the end of June. Both platforms define normal flows using a seven-day moving average of transit calls through the strait based on port transit data.

Ship movements through the strait remain well below prewar levels. On Wednesday, eight ships crossed the waterway, including three oil tankers, compared with more than 100 ships a day before the conflict began.

State television released footage showing masked commandos boarding the MSC Francesca and the Epaminondas. Iranian authorities described the vessels as captured after attempting to transit without permission.

U.S. personnel boarded a tanker identified as the Majestic in the Indian Ocean; the vessel matched a supertanker last reported off Sri Lanka and carrying roughly 2 million barrels of crude. President Donald Trump posted that the U.S. Navy has “total control over the Strait of Hormuz,” adding the route was “Sealed up Tight,” and warned he would “shoot and kill” any boat laying mines in the strait.

Ulrike Hoffmann-Burchardi, chief investment officer for the Americas at UBS, wrote that reopening the strait “remains elusive,” and noted comments from Mohammad Bagher Ghalibaf, speaker of Iran’s parliament, who said the waterway would not reopen while a U.S. naval blockade remains in place. Hoffmann-Burchardi added that a prolonged period of higher energy prices could weigh on economic growth.

Diplomatic efforts have continued with conditions attached. A senior Iranian source indicated Tehran could consider attending a proposed meeting in Pakistan only if the U.S. blockade is lifted and seized Iranian ships are released. Peace talks collapsed days earlier, shortly before a two-week ceasefire expired, after which Iranian forces appeared to assert control over the strait.

Market participants and shipping groups are tracking daily transit counts for signs of recovery. For now, seizures, filmed boardings, U.S. naval action and public statements from both capitals have pushed reopening bets further into the coming months, and energy traders have reacted to the security threats.