US x Iran Effective Ceasefire by July 31?

Prediction markets put the probability at 16%: US x Iran Effective Ceasefire by July 31. Currently, markets see this as unlikely (16% YES). The US-Iran ceasefire has effectively ended with relatively more intense and consistent exchanges of fire in the Persian Gulf.

What’s Happening

The US-Iran effective ceasefire by July 31 question has moved sharply toward "no" after the Institute for the Study of War assessed on July 13, 2026 that the truce "has effectively ended," citing more intense and consistent exchanges of fire across the Persian Gulf. The Islamic Revolutionary Guards Corps (IRGC) Navy announced on July 11 that it had closed the Strait of Hormuz and struck a Cyprus-flagged vessel, followed by a second unspecified ship on July 12. In response, the United States launched strikes on dozens of Iranian military targets on July 12, part of a campaign that has now exceeded 300 strikes inside Iran, aimed at degrading Tehran's capacity to threaten shipping. [Understandingwar, Jul 14]

The underlying agreement — a memorandum of understanding President Trump signed last month at Versailles — was meant to make a cease-fire permanent and open a negotiating window of up to 60 days. The Atlantic reported on July 15 that the two nations have "essentially remained at war ever since," with Iran calculating it has little to lose from continued hostilities. Hawks argue the intensified US blockade of Iran's southern ports, reinstated in July 2026, is degrading Tehran's leverage; analysts caution that each maritime clash makes a durable us x iran effective ceasefire by july 31 less attainable. On July 16, Qatar denied Israeli media reports it had agreed to join military action against Iran. [The Atlantic, Jul 15]

Enforcement is intensifying: on July 17, US Marines from the 11th Marine Expeditionary Unit boarded and inspected the Iran-flagged tanker Wen Yao, underscoring an active blockade rather than de-escalation. The structural factor determining whether a us x iran effective ceasefire by july 31 holds is Strait of Hormuz traffic — with Tehran declaring the waterway closed and Washington enforcing transit by force, no negotiated pause has stabilized. Whether the ceasefire is judged "effective" will hinge on a sustained halt to strikes before the deadline. [Crypto Briefing, Jul 17]

Traded on Polymarket — $164K Volume

Polymarket prices this at 16c YES with $164K in volume. Moderate liquidity — use limit orders for positions above $1K to avoid moving the price.