Where the truth comes from: oracles & settlement
After the event, something has to declare the winner. That “something” is the oracle — and the rules differ.
An oracle reports the outcome
Resolution needs an agreed source of truth — an “oracle.” It can be an official data feed, a named publication, a review committee, or a decentralized vote. Crucially, the oracle (not the news) determines who gets paid.
Optimistic oracles (Polymarket / UMA)
Polymarket uses UMA's optimistic oracle. After the end date, anyone can propose the outcome on-chain; a challenge window opens; if no one disputes it, it's accepted and winning shares redeem for $1 in USDC. A disputed result escalates to a vote by UMA tokenholders, who research and settle the answer.
Named sources & committees (Kalshi)
A CFTC-regulated exchange like Kalshi settles against a specific, named source of truth with a defined review process, all spelled out in the contract's written rules before trading begins.
Creator resolution (Manifold)
On play-money venues, the person who created the market resolves it — flexible and fast, but only as reliable as that creator. Whatever the venue, skim the resolution criteria before you trust a price; PredictionHub surfaces the exact model on each market.
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