
Polymarket prices a formal US-Iran nuclear deal by year-end 2026 at just 95% (before 2027) versus Kalshi's 78% before January 2029—a 17-point gap reflecting their 752-day resolution window difference. Both platforms agree a comprehensive nuclear accord remains unresolved: the June 17 Islamabad Memorandum defers final nuclear terms to 60-day talks ending late August, leaving technical details on enrichment limits and uranium stockpiles to negotiate.
Background, methodology, and platform context
Compare nuclear deal prediction market odds side by side across Kalshi, Polymarket. Platforms show similar odds, with an average spread of just 0.0pp. Close agreement often signals strong market consensus. With $5.97M in combined trading volume across 9 outcomes, this is one of the most actively traded cross-platform prediction markets.
Descriptions normalized for comparison (outcome names replaced with [OUTCOME])
If the United States has agreed to, signed, or accepted a new Iran-US nuclear deal before Oct 1, 2026, then the market resolves to Yes.
An agreement also made with other countries (i.e. multilaterally) is still encompassed if the United States participates. "A new Iran-US nuclear deal" means a formal written agreement signed by authorized representatives of both the United States and Iran that (1) imposes verifiable restrictions on Iran's nuclear program, including limits on uranium enrichment, centrifuge numbers, or nuclear facility operations, AND (2) provides for the lifting, suspension, or modification of at least one US economic sanction on Iran in exchange for Iran's nuclear commitments. Clarification (04/19/26): The Agreement Long rulebook variable defines the nature of the qualifying instrument: it must be a formal written agreement signed by authorized representatives of both governments. It does not impose a precondition that the signing itself must occur before resolution. Because the Payout Criterion is satisfied if the United States has "agreed to, signed, or accepted" such an instrument, both governments publicly and officially agreeing to the terms of what will be a qualifying written agreement is sufficient to resolve the market to Yes, even if the formal signing has not yet taken place. Clarification (06/02/26): A qualifying instrument must impose "verifiable restrictions on Iran's nuclear program." A restriction is "verifiable" only where it establishes a concrete, objectively ascertainable standard (a defined limit, prohibition, quantity, or monitoring provision) against which compliance could in principle be confirmed; a general expression of intent that fixes no such standard is not considered “verifiable” for the purposes of this event. Accordingly, a bare pledge not to develop or pursue nuclear weapons, unaccompanied by any concrete limit on Iran's nuclear materials, activities, or facilities, does not on its own satisfy criterion (1). Conversely, a commitment to completely 'stop' or ‘suspend’ a specific nuclear activity (such as uranium enrichment) establishes a concrete prohibition (an implicit limit of zero) and qualifies as a restriction, whereas a vague promise to 'reduce' activities without a defined metric or monitoring mechanism does not. The enumerated examples (limits on uranium enrichment, centrifuge numbers, or nuclear facility operations) are illustrative and not exhaustive: a formal, verifiable commitment to remove, transfer, or cap Iran's stock of enriched uranium, confirmable by the receiving state or an oversight body, is a restriction on Iran's nuclear program and satisfies criterion (1). In every case, criterion (2) must independently be met.
This market will resolve to "Yes" if an official agreement over Iranian nuclear research and/or nuclear weapon development, defined as a publicly announced mutual agreement, is reached between the United States and Iran by July 31, 2026, 11:59 PM ET. Otherwise, this market will resolve to “No”. If such an agreement is officially reached before the resolution date, this market will resolve to "Yes", regardless of if/when the agreement goes into effect. Agreements that include the United States and Iran as parties, even if they also involve other countries (e.g., a multilateral deal like the JCPOA), will qualify for resolution. The primary resolution source for this market will be an official announcement by the United States and/or the Islamic Republic of Iran, however an overwhelming consensus of credible reporting confirming an agreement has been reached will also qualify.
Different platforms may use different resolution criteria, data sources, and settlement timelines.