Iran charges Hormuz fees by August 31?

Prediction markets put the probability at 12%: Iran charges Hormuz fees by August 31. Currently, markets see this as unlikely (12% YES). The Iranian island of Kharg in the Persian Gulf, August 31, 2002.

What’s Happening

The question of whether Iran charges Hormuz fees by August 31 has moved from diplomatic speculation to active legislative action, with Iran’s parliament advancing a bill that would impose transit fees on vessels passing through the Strait of Hormuz and bar ships linked to certain nations. This legislative push comes as the conflict entered its 31st day in late March, with both Tehran and Washington escalating military operations, though a ground offensive is considered unlikely to deliver a decisive outcome. The proposed fee structure, reported in early August, would see Iran collect a toll equal to 5% to 7% of cargo value, with Oman receiving an additional 3%, bringing the total transit cost to roughly 8% to 10% for shippers using the critical waterway [CGTN, Mar 31][Benzinga, Aug 07].

The commercial stakes are significant, as shipowners have already signaled they would redistribute any Hormuz-related charges across other voyage legs, meaning the cost would not stay contained to Gulf-bound cargo but would ripple through global supply chains. This comes after President Donald Trump briefly floated a 20% toll on cargo transiting the strait in mid-July, only to reverse course within a day in favor of Gulf trade deals and investment agreements with Middle Eastern countries. Meanwhile, oil prices have remained stable around $80 per barrel due to alternative supply routes, but traders remain cautious about a full shipping recovery, with prediction market data showing a 76% chance that fewer than 40 ships will transit the strait daily by August 31 [Scrippsnews, Jul 14][Pluang, Aug 10].

The structural factor determining whether Iran charges Hormuz fees by August 31 hinges on the expiration of a toll-free period that ends mid-August, after which Tehran has stated it will begin collecting fees despite ongoing diplomatic talks hinting at a reopening without tolls. The Iran-Oman management agreement currently in negotiation would formalize the revenue split, but its fate is tied to broader U.S.-Iran tensions, including American strikes on Iranian ports and Iranian attacks on U.S. allies in the region. With the toll-free window closing and both sides maintaining military pressure, the market’s 12% YES probability reflects skepticism that Iran can enforce the fee regime amid active conflict, though the legislative momentum and the proposed 8-10% total toll suggest the mechanism is fully prepared for implementation [Pluang, Aug 10][Benzinga, Aug 07].

Traded on Polymarket — $933K Volume

Polymarket prices this at 12c YES with $933K in volume. Moderate liquidity — use limit orders for positions above $1K to avoid moving the price.