US-Iran Final Nuclear Deal by…?

Platform comparison

Market context

The live issue is whether Washington and Tehran will turn the June 2026 framework into a *new written instrument* that is mutually signed or formally adopted by 31 August 2026, not whether talks continue. The market should therefore be read as a document-completion event: a signed protocol, memorandum, or other qualifying diplomatic text matters more than headline language about “progress”, because the June framework already started a 60-day negotiation clock and left the hard nuclear issues unresolved.[2][4][13]

For probability framing, the closest analogue is the 2015 nuclear deal process, where months of interim understandings and technical drafts mattered before any final text was concluded. In this round, Reuters reported on 12 June that a signing ceremony was being considered and that a 60-day negotiation period would follow, while AP later reported an initial deal had been signed and the next phase would address Iran’s nuclear programme.[8][13] That history cuts both ways for a market at 0%: once a draft exists, finalisation can happen quickly, but deadline risk remains high because any technical dispute over enrichment, inspections, sanctions relief, or sequencing can stop a formal instrument from emerging.[10][14]

A practical trader workflow is to monitor the announcement stream and encode it as a simple state machine: draft announced, signed/adopted, amendments issued, or talks extended without signature. The key catalysts are mediator readouts, any confirmed signing venue, and whether the parties publish a text with binding language on the nuclear file, sanctions, and implementation timetables.[2][8][16] Reuters and AP have each flagged the signing process and the follow-on negotiation window, so those updates are the ones most likely to move conditional orders or trigger a programmatic re-price before the settlement cutoff.[8][13][16]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

We track US-Iran Final Nuclear Deal by…? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

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.

UK Frequently Asked Questions

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Bot UK. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

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Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.