Every market has to answer one question when the event is over: what actually happened? The mechanism that decides is the resolution source, and it is the single biggest determinant of how trustworthy a market is. Understanding sources — and what happens when they are challenged — is essential before you put money down.
Resolution sources
A well-designed market names a specific authority that determines the outcome: an election board for a race, a government release such as the BLS or BEA for economic data, a governing body for a sports result, or a company’s official filing for earnings. The more specific and objective that source, the cleaner the resolution. Vague wording — a market that does not say exactly who decides or what counts — is a warning sign, because it leaves room for dispute. This is the deeper layer beneath the overview in how markets resolve.
Oracles and on-chain resolution
Crypto-native platforms such as Polymarket resolve through an oracle — a mechanism that reports the real-world result onto the blockchain so settlement can happen automatically. A widely used design is the “optimistic” oracle: someone proposes the outcome, and it is accepted as final unless another participant challenges it within a set window. Most of the time the proposed answer is obviously correct and stands without objection.
When outcomes are disputed
If a proposed resolution is wrong or ambiguous, it can be disputed. In an on-chain system, a challenge escalates the market to a dispute process in which token holders vote on the correct outcome, and both the proposer and the challenger post bonds that are at risk if they are wrong. Disputes usually stem from genuinely ambiguous criteria or unusual edge-case events. While a market is in dispute, settlement is paused and your funds stay locked until it is resolved — a real, if occasional, cost of trading ambiguous markets.
Protecting yourself
The defence is the same discipline that underpins everything else: read the resolution criteria and the named source before you trade, favour markets with clear and objective sources, and be wary of loosely-worded ones — especially in categories like tech and AI where milestones are easy to define ambiguously. Know how your platform’s dispute process works so a delay does not catch you off guard. For more on the errors this prevents, see common mistakes to avoid.
Frequently asked questions
How do prediction markets decide the outcome?
Each market names a resolution source — an authority such as an election board, a government data release, a sports governing body or a company filing — that determines what happened. The more specific and objective the source, the more reliable the resolution.
What is an oracle in a prediction market?
An oracle is a mechanism that reports a real-world outcome onto the blockchain so an on-chain market can settle. A common design is the optimistic oracle, where a proposed outcome is accepted as final unless someone challenges it within a set window.
What happens if a resolution is disputed?
A challenge escalates the market to a dispute process; on-chain, token holders vote on the correct outcome and both sides post bonds that are at risk if wrong. Settlement is paused and funds stay locked until the dispute is resolved.