Polymarket

A Polymarket market is a single binary question with Yes and No outcomes, identified by a condition ID, a question ID and token IDs. Each outcome is a token redeemable for one dollar if that outcome occurs. Events group one or more related markets, and multi-market events can link mutually exclusive outcomes as a negative-risk group. [1]

Shares trade between zero and one dollar, and the price is read as the market’s probability for that outcome. Prices emerge from a central limit order book where users trade with each other; an operator matches compatible orders off chain and matched trades settle through smart contracts on chain, so users keep custody. Outcome tokens are ERC-1155 tokens on Polygon, and every Yes/No pair is backed by one dollar of collateral locked in the conditional token contract. Splitting a dollar creates one of each token and merging a pair returns it. [2]

Resolution uses the UMA Optimistic Oracle. Anyone can propose an outcome by posting a bond, and a challenge period follows; disputes trigger a second round and, if disputed again, a vote by UMA token holders. After resolution winning tokens redeem for one dollar each and losing tokens are worth nothing. The documentation advises reading a market’s resolution rules, not just its title, before trading. [4]