OpenAI IPO by 2026?

Platform comparison

Market context

OpenAI would need to complete a public listing on a recognised exchange before the settlement deadline, and the current 1% implied probability means the market is pricing that as a very low-probability path. The practical read for a bot user is that the event requires a hard confirmation, not just vague IPO preparation: a confidential filing, target valuation talk or banker hiring is not enough unless the company actually prices and lists shares.

Historically, markets like this tend to move only when the issuer makes a formal timetable public or when reputable reporting narrows the window. Reuters reported in June that OpenAI had filed confidentially and was aiming for an IPO as early as September, but also that the timing was still undetermined and the company said it might be “a while” because some tasks are easier while private.[4][12] Later coverage from Reuters and the *New York Times* indicated the company was leaning towards delaying until 2027, which matters here because a 2026 settlement requires a much faster sequence of regulatory and market steps than the later reporting suggests.[5][9]

For a programme-driven workflow, the key catalysts are easy to wire into alerts: any official S-1 becoming public, a company statement naming an exchange or pricing window, underwriter-led roadshow scheduling, and credible reporting that confirms pricing rather than intent. Reuters’ reporting also placed Goldman Sachs and Morgan Stanley on the deal, so traders monitoring this market would typically key off filings, roadshow timing, and any reset in the company’s own language from “planning” to “launching”.[4][12]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

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.

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.

Is Polymarket legal in the UK?

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%.