US-Iran nuclear deal by May 31?

Platform comparison

Market context

The question hinges on whether the United States and Iran will publicly announce a mutual agreement addressing Iranian nuclear research or weapons development by the end of May 2026. The 17% crowd probability reflects significant scepticism about diplomatic breakthrough within an 18-month window, particularly given the current geopolitical climate and the breakdown of the Joint Comprehensive Plan of Action (JCPOA) in 2018.

Historical precedent suggests such negotiations move slowly. The original JCPOA took roughly two years of intensive multilateral talks (2013–2015) to conclude, whilst the 2015 agreement itself required years of preliminary discussions. The Trump administration's withdrawal in 2018 and subsequent reimposition of sanctions created a structural obstacle that subsequent administrations have struggled to overcome. Iran's nuclear programme has advanced considerably since the JCPOA's collapse—uranium enrichment levels and stockpiles have grown—which typically raises the negotiating complexity and time required to reach consensus. Comparable nuclear agreements with other states (North Korea, Libya) have similarly taken extended periods or failed entirely, suggesting 18 months is a compressed timeframe for resolving entrenched positions.

Near-term catalysts remain sparse. The Biden administration pursued indirect talks through intermediaries in 2021–2022 without producing a new accord. The incoming Trump administration in 2025 has historically opposed the JCPOA framework. Any meaningful shift would likely require either a dramatic change in US political stance, a major Iranian policy reversal, or an external crisis forcing both parties to the negotiating table. Analyst consensus across major policy institutes remains cautious; few expect formal agreement before mid-2026, though the possibility of preliminary frameworks or confidence-building measures cannot be ruled out entirely.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). The odds column is filled only where we have clean data — that avoids the made-up numbers that get a network demoted when search engines cross-check against the source venue.

Resolution & payout

Polymarket-based markets settle through the UMA Optimistic Oracle on Polygon. A proposer submits the outcome, a two-hour challenge window opens, and unchallenged proposals finalise the resolution. Payouts settle automatically in USDC the moment the result is final — no bookmaker, no delay.

Kalshi-based markets settle in USD via the CFTC-regulated clearinghouse. Betfair Exchange settles in GBP/EUR net of commission. Manifold is play-money and does not pay out real funds.

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.

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.

Do I need to KYC for this market?

Not under $1,500 of lifetime trading volume. Above that threshold, PolyGram triggers a quick verification flow that finishes in minutes.