Cancelled and Invalid Markets
Definition
A cancelled or invalid market is one whose event cannot be resolved yes or no under its rules, because the event did not take place as defined, the source failed, or the question had no clear answer. Rather than reversing trades, venues generally settle such markets at a value set by the rules: an even split, the last fair price, or a value between $0 and $1.
Why it matters
A split or fair-value settlement can produce a loss or a gain relative to the price paid; a contract bought at 80 cents and settled at 50 loses 30 cents. Investors should read each market's provisions for postponement, non-participation and invalid outcomes before trading, especially on sports and multi-leg products.
Common misconceptions
- •Cancelled does not mean refunded.
- •A 50/50 settlement pays $0.50 per contract whatever you paid.
- •Settled outcomes are final; later facts do not reopen them.
- •The label is only a starting point. Investor outcomes usually depend on the governing documents, cash-flow priority, valuation policy, disclosure quality, and manager discretion surrounding the term, not just the shorthand definition used in marketing materials.
Technical details
Settlement values used instead of $1 or $0
Polymarket: Unknown/50-50, each token redeems for $0.50.
Kalshi: last fair market price, or a non-standard payout such as 50-50, under the market's rules.
Kalshi protected NFL player markets: fair price before kickoff under stated conditions.
Kalshi combos: product of component values, including adjusted components.
How investors apply the term
Investors usually apply this term by tying the definition back to the controlling documents and then asking which cash flows, rights, restrictions, or valuation assumptions it changes. A useful review looks at the term alongside fees, leverage, liquidity, reporting frequency, and manager discretion rather than treating it as a standalone concept.
The practical diligence test is simple: identify who benefits if the assumption is wrong, who has control when conditions change, and what evidence the investor receives after closing. Terms that cannot be reconciled to documents, cash movements, and monitoring data should be treated as marketing shorthand until proven otherwise.
Frequently asked questions
- What happens to my money if an event market is cancelled?
- It is usually settled at a rule-defined value, not refunded. On Polymarket, an 'Unknown/50-50' resolution means 'each token redeems for $0.50.' Kalshi says some markets 'can resolve to the last fair market price or a non-standard payout like 50-50,' and in player markets a player who does not play is settled under the market's specific rules, often at a fair value.
- Is a combo refunded if one leg is voided?
- No, on Kalshi. 'A DNP does not on its own refund or cancel the combo.' The combo pays the product of its components' values, so a leg settled at $0.70 and two legs at $1.00 pay $0.70 per contract. Kalshi also says that once a combo 'is placed and filled, it cannot be canceled or reversed by the user.'
- Can the venue reverse a resolution?
- Generally no. Polymarket says it 'is non-custodial and cannot alter or reverse market resolutions. Once finalized by UMA, outcomes are immutable.' Kalshi says markets 'are not re-settled because an event appears to have concluded while trading was still available.'