Platform comparison
| Platform | YES odds | NO odds | Fee | KYC | Settlement | |
|---|---|---|---|---|---|---|
Polymarket (via Polymarket Alternative UK) Pick polygram.ink (preferred broker) |
99% | 1% | 0% (USDC on-chain) | No-KYC up to $1,500 | USDC, auto via UMA oracle | View on Polymarket → |
Polymarket (direct) polymarket.com |
99% | 1% | 0% | Geo-blocked in US/UK/EU | USDC, on-chain | View on Polymarket → |
Kalshi kalshi.com |
— | — | Up to 7% per trade | US-only, KYC required | USD | View on Polymarket → |
Betfair Exchange betfair.com |
— | — | 2-5% commission | Full KYC from first trade | GBP / EUR | View on Polymarket → |
Manifold Markets manifold.markets |
— | — | Play-money (mana) | None — play-money | Mana (no cash-out) | View on Polymarket → |
Outcome probabilities
Current market-implied probability for each outcome, from the live order book.
| Outcome | Probability |
|---|---|
| Anthropic | 99% |
| 0% | |
| OpenAI | 0% |
| Alibaba | 0% |
| Z.ai | 0% |
| xAI | 0% |
| DeepSeek | 0% |
| Moonshot | 0% |
| Mistral | 0% |
| Meituan | 0% |
| Microsoft | 0% |
| Meta | 0% |
| Amazon | 0% |
| Baidu | 0% |
| ByteDance | 0% |
| Company A | 0% |
| Company B | 0% |
| Company C | 0% |
| Company D | 0% |
| Company E | 0% |
| Company F | 0% |
| Company G | 0% |
| Company H | 0% |
| Company I | 0% |
| Company K | 0% |
| Other | 0% |
Market context
The Chatbot Arena leaderboard ranks large language models by user preference through head-to-head comparison voting. On 31 July 2026, this market resolves to whichever company owns the model sitting atop that ranking. Polymarket currently prices this contract at 0% YES, reflecting either extreme confidence in a specific outcome or insufficient liquidity to establish a meaningful price. The settlement mechanism pulls directly from the leaderboard's "Rank" column with Arena score as the tiebreaker, removing subjective interpretation from resolution.
Historical precedent suggests the leaderboard leadership rotates amongst a narrow set of competitors. OpenAI's GPT-4 variants have dominated Chatbot Arena since its inception, though Claude models from Anthropic have periodically challenged that position following major releases. Google's Gemini and Meta's Llama have gained ground in recent rankings but have not yet held the top position consistently. The 0% implied probability suggests traders expect one incumbent to maintain dominance through mid-2026, though this pricing may simply reflect low trading volume rather than genuine certainty.
Catalysts centre on model release schedules and leaderboard voting patterns. OpenAI typically announces capability updates in spring or autumn; Anthropic released Claude 3.5 Sonnet in June 2024 and may follow a similar cycle. The leaderboard's voting mechanism itself introduces volatility—user preferences shift with interface changes, new benchmark tasks, or shifts in what tasks users prioritise testing. Any major release from a challenger within six months of the settlement date could materially alter rankings, whilst stagnation from the current leader creates opening for displacement.
Methodology
This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to Polymarket Alternative UK, which mirrors the Polymarket order book directly.
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?
- Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Polymarket Alternative 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.
- 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 does Polymarket cost to trade?
- Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.
- 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.
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