Traders pull Hormuz traffic odds back to even

Traders expect 21 to 30 Hormuz transit calls last week; tomorrow's tally decides whether the count topped 25.

In one line: PortWatch will count more than 25 Hormuz transits for 21 to 27 September, because Iran's last-day warning came too late to cut the week's total.

Iran's body for managing the Strait of Hormuz said on 27 Sep that ships using unauthorised routes will face serious restrictions, the Sunday Guardian reported. The warning fell on the last day of the week this Kalshi contract counts. A transit call is one passage through the strait by a ship, as logged by IMF PortWatch. The contract pays Yes if the number of transit calls "is above 25 from Sep 21, 2026 to Sep 27, 2026".

Traders cut the contract from 58% on 21 Sep to a low of 21% on 27 Sep, then lifted it 32 points to 53%. It rose 14.0 points in the last 24 hours. The rest of the ladder narrows the question. More than 20 calls trades at 96% and more than 30 at 8%, so traders expect a count between 21 and 30. Kalshi's peak-day contract, which asks about the busiest single day of the same week, prices more than five calls at 92% and more than ten at 4%.

The best reading of the slump is a scare the calendar had already overtaken. Restrictions announced on 27 Sep govern ships from then on; they cannot undo passages made earlier in the week. The 14-point rise in the last 24 hours came as the measurement window closed. The busiest-day prices fit this reading, because a week above 25 needs no single day above ten, only an average of just under four calls a day, assuming calls are spread across the week.

PortWatch will report more than 25 transit calls for the week, and the 53% price looks low, because the only reported threat to traffic came on the week's last day. The main risk is that the count lands at 25 or below, since the 8% price on more than 30 calls shows traders see little spare room above the line. The call is wrong if PortWatch's figure for 21 to 27 September, on which the contract settles on 29 Sep, is 25 or fewer.

Sources