US-Iran nuclear deal by May 31?

Platform comparison

Market context

Polymarket currently prices a US-Iran nuclear agreement by end-May 2026 at 19% YES, implying traders assess a roughly one-in-five chance that Washington and Tehran will announce a formal mutual accord on nuclear research or weapons development within the next 18 months. The market settles on announcement alone; ratification or implementation timelines are irrelevant to resolution. This compressed probability reflects the substantial diplomatic distance between the parties and the compressed timeframe relative to historical negotiation cycles.

The 2015 Joint Comprehensive Plan of Action (JCPOA) took roughly two years of intensive talks to conclude, whilst the Trump administration's 2018 withdrawal and subsequent "maximum pressure" campaign created a 2020–2024 period of escalating tensions, uranium enrichment, and proxy conflicts. The Biden administration attempted indirect negotiations through Oman and Qatar from 2021 onwards without achieving a breakthrough. Any new accord would require either a significant shift in Iranian domestic politics, a change in US administration priorities, or both—neither of which the current trajectory suggests is imminent.

Key catalysts include statements from Iran's government following its February 2024 ballistic missile tests and any formal US diplomatic overtures. Reuters reported in late 2024 that indirect talks had stalled, with both sides citing preconditions the other deemed unacceptable. Traders should monitor announcements from the UN nuclear watchdog (IAEA), statements by European intermediaries, and any shifts in US policy following the 2024 election cycle. A sudden escalation in Israeli-Iranian tensions or a major shift in regional proxy conflicts could either accelerate or derail negotiations 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

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.

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.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.