The distinction matters when a headline looks conclusive but a position is still unresolved. A price records what people will pay. It does not, by itself, decide which interpretation of the contract will release the payout.
This article examines public documentation checked on 14 September 2026, including Kalshi's exchange rulebook v1.29 and the rulebook linked by Polymarket US. It is a product explainer, not a recommendation to trade or advice on an individual legal claim.
The first dispute can be about the question
Consider a hypothetical market asking whether a company will open a factory by the end of June. A ribbon-cutting happens on 30 June. Production starts on 2 July. One person points to the ceremony; another points to the first manufactured product. Neither observation settles the contract until the word “open” has a defined meaning and an accepted source.
This is an illustration, not a reported market or a quotation from an actual contract. Its purpose is to expose three separate questions: what happened, what the contract required, and who is authorised to connect the two.
Kalshi's help centre explicitly distinguishes its short rules summary from the full contract rules. The latter are available through “View full rules”. A summary can help a reader navigate, but it is not the complete specification. Kalshi's explanation of rules summaries.
Our prediction markets versus sports betting guide covers pricing and counterparties. Here, the concern is what happens after those prices have done their job.
Three products, three resolution authorities
| Product | Who determines or reviews the outcome? | What must not be assumed? |
|---|---|---|
| Kalshi | Kalshi determines outcomes from the contract's rules and source; its Outcome Review Committee handles reviews initiated under Rule 7.1. | A customer complaint does not automatically initiate that committee process. |
| Polymarket International | An outcome is proposed through UMA; a second disputed proposal can escalate to UMA's Data Verification Mechanism, or DVM. | Every proposal has identical eligibility rules or an identical challenge deadline. |
| Polymarket US | The exchange determines the outcome; specified officers or their designate can initiate the review described in Rule 10.4. | The international UMA procedure applies to the US exchange. |
The sections below identify the governing documents and limits of each comparison. Fees, access and funding are separate questions covered in our Kalshi and Polymarket product comparison.
Kalshi: a committee process, not a vote by position holders
Kalshi says it determines an expired contract's outcome using the rules and source specified in that contract. The final data may arrive after the event people have been watching. Kalshi's market-outcome documentation.
Rule 7.1 of its exchange rulebook gives Kalshi discretion to initiate a Market Outcome Review Process before settlement when circumstances may materially affect the underlying event's reliability or transparency. The Outcome Review Committee then determines the result, and Kalshi posts that the outcome is under review.
The rule sets a 24-hour period for the committee's determination after the process starts and describes its determinations as final. That clock is not a promise to settle every contract within 24 hours of the event ending. Nor does the rule say that sending a support message automatically opens a review. Kalshi exchange rulebook v1.29, Rule 7.1.
For a pending market, Kalshi's practical guidance is to check the specified determination time and provide the market title and source details when contacting support. Its help page also warns that trading close time and determination time can differ. An unresolved screen is therefore not, on its own, evidence of a disputed decision. Kalshi's settlement FAQs.
Polymarket International: proposals can become oracle disputes
An oracle brings an external answer into a blockchain-based system. In Polymarket International's published overview, a proposer submits an outcome with a bond. If a proposal is not challenged within the applicable window, it can be accepted. A challenge leads to another proposal round; if that second proposal is also disputed, the process can reach UMA's DVM for a vote.
Polymarket's overview describes a two-hour challenge period and says unforeseen circumstances may require additional rule context, published onchain without changing the question's fundamental intent. These are features of its international documentation, not the US exchange rulebook. Polymarket International's resolution overview.
There is an important qualification. UMA's own integration guide also describes managed requests with a proposer whitelist and challenge periods that can be extended after a proposal is flagged. Its prediction-market lifecycle distinguishes a first disputed request from the later request that governs settlement. The general Polymarket overview and the more detailed UMA guide are not interchangeable descriptions of every live request. Check the actual request, applicable rules and displayed deadline; do not infer universal access or a fixed two-hour timer from an explainer. UMA's prediction-market integration guide.
The DVM is not a poll of everyone holding a position in that event. UMA documents participation through staked UMA tokens, with commit-and-reveal voting and penalties for incorrect or missed votes. It also describes votes rolling into later rounds when required participation and agreement thresholds are not met. That helps explain why a contested oracle process cannot safely be reduced to “the event finished, so payment is due now”. UMA's DVM documentation.
Polymarket US: the exchange retains the decision
Polymarket US says the exchange determines results against the market's criteria and named sources. Its resolution guide distinguishes government data, governing sports bodies and specifically named news outlets; an unrelated report is not automatically an accepted resolution source. Polymarket US's resolution guide.
Rule 10.4 of the linked exchange rulebook permits specified senior officers, or their designate, to undertake a pre-settlement review of circumstances affecting the underlying event's reliability or transparency. The company can determine the final outcome and reverse an outcome in the case of obvious error. Participants are notified of the determination, including through the website and system notifications. The rule describes the company's determinations as final. Polymarket US exchange rulebook, Rule 10.4.
Reading only the international oracle guide would miss that allocation of authority. A shared brand does not create a shared appeals procedure.
Resolution also precedes the financial settlement step: Polymarket US says Polymarket Clearing processes settlement and balance updates after the outcome is finalised. Some contracts specify alternative settlement terms. A disputed result, a balance update and a bank withdrawal should not be treated as one interchangeable problem. Polymarket US's settlement guide.
A useful complaint identifies the exact disagreement
The following is an editorial checklist for describing a problem, not a substitute for a platform's submission procedure or deadline:
Identify the exact product and contract, not just the platform brand or event headline.
Preserve the applicable full rules, named source, relevant timestamps and any published clarification.
Separate disagreement with the evidence from disagreement with how the rule was interpreted.
Record the current state: awaiting source data, proposed, challenged, under review, resolved or settled.
Use the route specified for that product. A public comment is not necessarily a formal oracle challenge or an exchange review request.
“Final” in a market-resolution procedure should not be read here as an assessment of every possible legal remedy. Those questions depend on the applicable agreements, facts and jurisdiction and require separate advice.
There is a familiar parallel in void, push and dead-heat sportsbook settlements: a disappointing return does not explain the rule that produced it. But sportsbook terminology cannot supply a missing prediction-market rule.
For a product team, the useful design question is whether a customer can move from the result on screen to the governing clause, source and decision record without guessing. An interface that shows those links makes disagreement inspectable. A payout badge alone leaves the most important question unanswered: who decided this, on what evidence, and under which rule?
