When the outcome of an event becomes known, the market is **resolved**. Resolution determines which outcome won, allowing holders of winning tokens to redeem them for \$1 each. Losing tokens become worthless.
Polymarket uses the **UMA Optimistic Oracle** for decentralized, permissionless resolution. Anyone can propose an outcome, and anyone can dispute it if they believe it's incorrect.
Every market has pre-defined resolution rules that specify:
* **Resolution source** — Where the outcome will be determined from (e.g., official announcements, specific websites)
* **End date** — When the market is eligible for resolution
* **Edge cases** — How ambiguous situations should be handled
<Warning>
Always read the resolution rules before trading. The market title describes
the question, but the **rules** define how it resolves.
</Warning>
<Steps>
<Step title="Proposal">
Anyone can propose a resolution by:
1. Selecting the winning outcome
2. Posting a bond (typically \$750 USDC.e)
3. Submitting the proposal to the UMA Oracle
If the proposal is correct and undisputed, the proposer receives their bond back plus a reward.
<Warning>
If you propose incorrectly or too early, you lose your entire bond. Only
propose if you're confident in the outcome and understand the process.
</Warning>
</Step>
<Step title="Challenge Period">
After a proposal, there's a **2-hour challenge period** where anyone can dispute the outcome.
* **If no dispute**: The proposal is accepted and the market resolves
* **If disputed**: A new proposal round begins. If the second proposal is also disputed, the resolution escalates to UMA's DVM (Data Verification Mechanism) for a token holder vote.
| **Proposer wins** | Original proposal accepted | Proposer gets bond back + half of disputer's bond |
| **Disputer wins** | Proposal rejected, new proposal needed | Disputer gets bond back + half of proposer's bond |
| **Too Early** | Event hasn't concluded yet | Disputer gets bond back + half of proposer's bond |
| **Unknown/50-50** | Neither outcome applicable (rare) | Market resolves 50/50 — each token redeems for \$0.50; disputer gets bond back + half of proposer's bond |
</Step>
</Steps>
## After Resolution
Once a market resolves:
* **Trading stops** — You can no longer buy or sell tokens for this market
* **Winning tokens** become redeemable for \$1.00 each
* **Losing tokens** become worthless (\$0.00)
### Redeeming Tokens
After resolution, call the `redeemPositions` function on the CTF contract to exchange winning tokens for USDC.e. The contract burns your tokens and returns the corresponding collateral.
In rare cases, unforeseen circumstances require clarification of the rules after trading begins. Polymarket may issue an **"Additional context"** update that proposers and voters should consider during resolution.
