The written condition controls
Resolution is the determination of a market’s outcome. Settlement is the application of the contract’s payoff, although platforms sometimes use these terms together. Start with the full rules, including the official source and any edge cases.
Two contracts can have similar titles and different winning conditions. An announcement, an appointment, and taking office are three different events. Never assume a familiar phrase has the same meaning across venues.
Read the source and the threshold
Identify the exact publication, agency, exchange, or other authority that supplies the result. Then check units, rounding, time zone, and whether a threshold is strict or inclusive.
In a hypothetical market, “above 2.5%” and “at least 2.5%” resolve differently if the governing observation is exactly 2.5%. A later data revision may or may not count. The contract’s rules decide which observation applies.
There can be several clocks
The end of an event, the close of trading, the determination time, and the availability of funds need not coincide. Kalshi’s settlement guidance explicitly distinguishes close time from determination and explains that official data can delay settlement.
Record these dates separately. A result reported in the news may precede the official publication required by the contract. Funds can remain committed while that process completes.
Resolution mechanisms differ
Kalshi describes its markets team finalizing outcomes using the relevant source. Polymarket’s international documentation describes an oracle process involving proposals and possible challenges. These are different systems with different procedures.
Find who can decide, what evidence counts, whether a challenge is available, and what happens during a dispute. Do not generalize the procedure of one product to every product offered under a similar brand.
Not every settlement is $1 or $0
The $1-or-$0 model describes ordinary binary settlement. Exceptional rules can produce other payouts: Kalshi’s market FAQs describe certain nonparticipation cases using fair market value, while Polymarket’s international resolution documentation describes an Unknown/50-50 outcome paying 50¢ per token. These are specific procedures, not a universal refund policy.
Check cancellation, postponement, unavailable-data, and ambiguous-outcome provisions before using binary payout arithmetic. Our calculator does not model those exceptional settlements.
A practical reading exercise
Before evaluating a contract, write a sentence completing: “This pays if [condition], measured by [source], for [period], under [revision and exception rules].” If any blank cannot be filled, the headline has not provided enough information.
Keep a copy of the relevant rules and market identifier. If an outcome is disputed, a precise rule reference and the named source are more useful than a screenshot of the headline alone.
Fact-check notes
Review completed .
- Added documented examples of exceptional payouts on Kalshi and Polymarket international, and clarified that the calculator covers ordinary binary settlement.
Sources & further reading
- Kalshi — Market settlement and payout FAQs
- Polymarket — Resolution
- Polymarket — How prediction markets are resolved
Platform terms and rules can change. Check the linked primary sources and the specific contract before relying on a detail. How we work →