UMA Optimistic Oracle — Prediction market glossary

The on-chain oracle Polymarket uses to settle markets: outcomes are proposed, can be disputed, and finalize optimistically if undisputed.

The UMA Optimistic Oracle is the resolution mechanism behind Polymarket. After an event ends, a proposer submits the outcome on-chain along with a bond. If no one disputes within the challenge window, the outcome finalizes “optimistically.” Disputes escalate to UMA’s decentralized voting. This makes every resolution publicly verifiable on-chain.