US-Iran nuclear deal by May 31?

Platform comparison

Market context

An official US-Iran nuclear agreement by 31 May is trading as a clear underdog at 12% implied probability, with the market consensus still leaning hard towards no deal. That makes “Yes” the contrarian side, but not an obvious value case: the path to a publicly announced mutual agreement is short, and past Iran nuclear diplomacy has usually moved in fits and starts rather than straight lines. The JCPOA took years to assemble, and the later attempts to revive it foundered on the same core disputes — uranium enrichment limits, stockpile reductions, inspections, sanctions relief and the status of the IRGC — which have repeatedly blocked closure even when talks were active.

The main catalysts are diplomatic signalling, not implementation details. Traders should watch for any formal announcement from Washington or Tehran, but also for evidence that negotiating sessions have been scheduled, that intermediaries such as Oman or the EU are shuttling revised text, and that either side is softening on enrichment or verification language. Recent reporting has suggested some progress in talks, while still noting that President Trump has rejected at least one proposal and that major disagreements remain, which helps explain why the crowd is pricing such a low chance of a signed deal by month-end. The near-term bull case for Yes rests on a surprise breakthrough or a narrowly worded interim agreement; the bear case is that even if talks continue, the calendar closes before any public accord is reached.

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page reviews US-Iran nuclear deal by May 31? across five venues. We show live odds for Polymarket-based markets (sourced from the Polygon order book); for other venues we list platform attributes, since the comparable contracts are not exposed via a public API on every venue. Every CTA points at PolyGram — the application we operate, where you trade directly against the Polymarket order book at 0% fees.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

On PolyGram, which mirrors the Polymarket order book at 0% fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

PolyGram is available in most jurisdictions where Polymarket isn't directly accessible. Polymarket itself is geo-blocked in the US/UK/EU. Always check local regulations.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.