GUIDE · How Event Contracts Settle: What Happens When You Disagree
How Event Contracts Settle: What Happens When You Disagree
Settlement is the moment a prediction market becomes real money. Every contract has a resolution: it pays $1.00 per YES share, or $0.00, or something in between. Most traders spend their time on entry prices and exit timing, and almost no time on the rules that decide what happens at the end. That is backwards. The settlement rules are the trade, and the cases below show what happens when the rules and the public expectation diverge.
This is the highest-frequency unanswered question in prediction market communities: what happens when the market settles and you disagree with the result? The honest answer, documented through the cases below, is that on both major platforms you have almost no recourse, and the platforms' own documents and regulators say so.
How Settlement Actually Works
A prediction market contract is a binary bet on a defined statement, for example "Will X happen before date Y?". When the event reaches its end date, the platform determines whether the statement is true or false. YES shares then pay $1.00 each. NO shares pay $1.00 each when the statement is false. In most cases the market settles cleanly and the payout is automatic.
The part traders skip is the definition of "true". That definition lives in the market's rules, and it is not always the plain reading of the question. Consider the documented case of the Iran market on Polymarket: the market asked whether the leader would be dead by a given date. When the leader died, the market did not settle at YES. It settled at 39.5%, because the rules contained a "death carveout" that traders said was not disclosed until after the event. A market that most holders expected to pay $1.00 paid about 39.5 cents instead.
That single case is the whole lesson: the resolution source, the effective date, and the carveouts in the rules determine the payout, not your reading of the question.
Case 1: The Khamenei Death Carveout
The market on the Iranian leader's death is the most cited settlement dispute in the niche, and it is the reason this guide exists. The market's rules allegedly included a carveout under which the contract would settle at a partial value, around 39.5% instead of the $1.00 that a "yes, he died" outcome implies. Traders who held YES at prices near $1.00 discovered the carveout only after the event resolved.
Whatever the exact terms, the pattern is what matters for every future trade: a carveout can change a near-certain payout into a partial one, and the rules are the only place that carveout lives. The question "did the event happen" and the question "what does the contract pay" are different questions. Settlement answers the second one.
This is also why reading the rulebook before trading is not optional. We have a full checklist in our guide How to Read a Market's Rulebook Before You Trade.
Case 2: The Spotify Payout
The second documented case shows the opposite failure: a market paid out on data that was about to be corrected. A market on Spotify streams paid out to YES holders minutes before Spotify deleted 523,000 fraudulent streams. The payout happened on the data as it existed at settlement time, and the correction arrived too late to matter.
This case demonstrates that settlement is timestamped. The question is not "what is true eventually" but "what is true at the moment the market settles". Data corrections, late news, and retroactive adjustments almost never change a payout, because the resolution source has already recorded its answer.
For traders the lesson is practical: if you hold a position whose value depends on data that could be revised, the risk is not the revision. The risk is that settlement happens before the revision does.
Case 3: The Massachusetts Attorney General Complaint
The most authoritative statement about Kalshi settlement comes from a government regulator. In a complaint about Kalshi, the Massachusetts Attorney General described the platform as one that "writes the rules for the contract, determines the basis for settlement" with no independent intermediary. That single sentence is the clearest description available of how settlement power is concentrated: the platform writes the rules, and the platform decides the outcome.
There is no independent oracle, no neutral referee, and no appeals body between the trader and the platform's settlement decision. The complaint also documents specific disputes: a Bitcoin market marked as a loss "despite price data supporting win", a market left open after the event it tracked had already resolved, an $89.27 hold on a winning bet, and a $25 referral bonus never credited despite repeated assurances from support.
None of these disputes went to a neutral third party. That is the structural reality of settlement disputes on this platform: the counterparty to the rules is also the judge of the rules.
What Your Recourse Actually Is
When you disagree with a settlement, the documented options are thinner than most traders assume:
- Platform support. The first and only normal channel. Its responsiveness is measurable: 174 of 214 complaints filed with the Better Business Bureau about Kalshi were unanswered, a rate of roughly 81%. Trustpilot reviews for the platform sit near 1.9 out of 5, with settlement and withdrawal complaints dominating the one-star theme.
- Better Business Bureau. A complaint there is public and sometimes prompts a response, but the BBB has no enforcement power over settlement outcomes.
- Regulators. The CFTC oversees Kalshi as a designated contract market and has a reparations process for customers. State attorneys general can act on consumer protection complaints, as Massachusetts did. These are real but slow, and they are not designed for individual payout disputes.
- Courts. The terms of service on both platforms generally route disputes through arbitration clauses. In practice, individual settlement disputes do not reach courts.
The pattern across all of these channels is the same: they exist, they are public, and none of them is a fast neutral referee for a single disputed payout. The rational response is not to fight settlements after the fact. It is to price the settlement risk before you enter, which is what the rulebook checklist is for.
What to Check Before You Trade, So You Never Need a Dispute
- Read the rules before buying. The resolution source, the effective date, and the carveouts are in the market's rule text. Ten minutes of reading prevents the Khamenei outcome.
- Identify the resolution source. Who or what decides the outcome: an oracle, an API, a committee, an exchange's own judgment? A market that resolves on a single source you cannot verify is a market with settlement risk.
- Check the effective date and the event definition. "Before date Y" means the event must occur by date Y. A market that stays open after the event resolved, as documented in the Massachusetts complaint, is a settlement defect, not a feature.
- Price the worst case. If a carveout could convert your near-certain YES into a partial payout, the expected value of the trade is lower than the price suggests. Run the numbers in our arbitrage calculator with a haircut for settlement risk.
- Size the position so a disputed settlement is survivable. If you cannot afford to lose the full stake on a rules dispute, the position is too large. Our Risk Management: The 5-Rule Framework covers position sizing in detail.
FAQ
Q: Can I appeal a settlement I disagree with?
A: On Kalshi, the documented record shows no independent appeals body. The Massachusetts Attorney General complaint states the platform "writes the rules for the contract, determines the basis for settlement" with no independent intermediary. Support tickets, BBB complaints, and regulator complaints are the available channels, and 81% of BBB complaints against the platform went unanswered.
Q: Can a market settle at a partial value?
A: Yes. The Khamenei death market settled around 39.5% rather than at $1.00 or $0.00, because a carveout in the rules changed the payout. Always read the rules for partial settlement conditions before buying.
Q: What happens if the data the market settles on is later corrected?
A: Nothing changes for the payout. The Spotify market paid out minutes before 523,000 fraudulent streams were deleted. Settlement uses the resolution source's data as it exists at settlement time; later corrections almost never revise a payout.
Q: Do Polymarket and Kalshi settle the same way?
A: No. Polymarket uses community-participated or oracle-based resolution depending on the market, while Kalshi is a CFTC-regulated designated contract market where the exchange sets the rules and determines settlement. Both concentrate the final decision with the platform, and neither offers an independent appeal mechanism.
Q: Is a settlement dispute the same as a voided market?
A: No. A voided market returns the cost basis to holders, usually because the event cannot be determined or the market was erroneous. A disputed settlement pays some value under contested rules. Voids return your money; disputes decide how much of it you keep.
Q: Where can I read the rules before I trade?
A: On Polymarket, open the market and read the rules section before placing an order. On Kalshi, the contract details page includes the rulebook for each market. Our guide How to Read a Market's Rulebook Before You Trade has the full checklist of what to look for.
Last updated: 2026-08-11