FlightAware sued Kalshi on 10 August in the US District Court for the Southern District of New York, case 1:26-cv-06824. The complaint alleges that the prediction market operator used FlightAware's proprietary flight data and its trademarks, without authorisation, to run contracts on airline cancellation rates.
The coverage has treated this as an aviation story with a betting angle. It is not. It is the first serious test of the layer every prediction market depends on and almost never discusses: the settlement source.
The sequence
According to the filing, Kalshi submitted a self-certification to the Commodity Futures Trading Commission in mid-July 2026 for contracts on the share of scheduled flights cancelled at specific airports over set periods. In that filing, Kalshi named FlightAware as the primary source agency — the authority whose numbers determine which side of the contract pays.
FlightAware says it had never agreed to that. It says Kalshi was contractually barred from using its data for commercial gambling or prediction market activity. Once it learned of the markets, it revoked Kalshi's access to AeroAPI, its commercial data product, and issued cease-and-desist notices.
The claims are breach of contract, trademark infringement under the Lanham Act, and unfair competition.
Why the "source agency" line matters more than the trademark line
Strip away the aviation specifics and the structure is familiar to anyone who has looked at an on-chain oracle.
A prediction market contract is only as good as the thing that resolves it. Somewhere in every contract's terms there is a named authority: a government statistics agency, a broadcaster's election desk, a sports league's official scorer, a price index, an API. That authority is the oracle. It is what converts a real-world event into a settlement instruction.
Almost all of those authorities are third parties who never signed up for the role.
A federal agency publishing CPI is not a counterparty to anyone's contract, and cannot object to being cited. A commercial data vendor is in an entirely different position. It has terms of service, a licensing business, a trademark, and a direct financial interest in who gets to build products on its feed. FlightAware is arguing that being designated a settlement authority in a CFTC filing is not a neutral act of citation — it is commercial use of its product and its name.
If that argument holds, the naming of a private data source in a contract specification becomes a licensing negotiation rather than a drafting decision.
What breaks if a source revokes mid-contract
The practical hazard is not the lawsuit. It is what happened before it.
FlightAware cut off API access. A contract whose resolution source has just terminated the venue's access is a contract with a resolution problem. Prediction markets generally reserve the right to use alternative sources or to resolve on the exchange's determination, but every fallback is a step further from the objective number the buyer thought they were trading.
For a market on flight cancellations at a single airport over a single week, that is a manageable mess. For the category as a whole, it is a modelled risk that no one has been pricing: source revocation. A settlement feed that can be switched off by a vendor with a commercial grievance is not a settlement feed, it is a dependency.
Decentralised prediction markets are not exempt. A dispute-resolution mechanism that asks token holders to vote on an outcome still needs someone to point at a number, and that number usually comes from a commercial API too.
The reputational overhang
The complaint also carries an argument that has nothing to do with data rights and will be harder for the sector to answer. Cancellation markets create a payoff for flights not departing. Critics have pointed out that this attaches a financial incentive to disruption at airports.
Whether that risk is realistic is debatable. Whether it is a useful headline for a CFTC currently deciding how much room to give event contracts is not.
What to watch
Three things. Whether Kalshi amends or withdraws the self-certification rather than litigate the source designation. Whether other data vendors — sports statistics providers, weather services, financial index operators — send their own notices once they see the theory tested. And whether the CFTC's self-certification process starts requiring evidence that a named source agency has actually consented to the role.
That last one would be the expensive outcome. It would convert a free input into a licensed one across an entire product category.