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2026年08月11日

A Lawsuit That Vanished in 24 Hours: Prediction Markets and the Question of Who Owns the Settlement Source

24時間で消えた訴訟 ― 予測市場が突きつけた「決済ソースは誰のものか」という問い

From Filing to Withdrawal in a Single Day

On August 10, 2026, FlightAware filed suit against Kalshi Inc. and three affiliated entities in the US District Court for the Southern District of New York. The complaint pleaded six counts including breach of contract, trademark infringement under the Lanham Act, unfair competition and unjust enrichment, and sought damages, permanent injunctive relief, and an emergency temporary restraining order.

The following day, August 11, FlightAware voluntarily dismissed the action. The dismissal was entered without prejudice under Federal Rule of Civil Procedure 41(a)(1)(A)(i), covering all four defendants, and it came before Kalshi filed any answer and before a judge ruled on the restraining order request.

Kalshi's flight cancellation markets are still operating. What changed was the wording. Pages that had told traders the "outcome verified from FlightAware" now read "outcome verified from Primary Source Agency," with the link still pointing to FlightAware's website. A disclaimer was added stating that the markets have not been endorsed by the Primary Source Agency and that any references are descriptive only.

The Fight Narrowed to the Name, Not the Data

The sequence set out in the complaint is specific. Kalshi opened a free Personal AeroAPI account with FlightAware on July 14, 2022, under terms that prohibit use in furtherance of any business. On July 14, 2026, Kalshi filed a self-certification with the Commodity Futures Trading Commission for contracts on the percentage of scheduled flights cancelled at particular airports, naming FlightAware as the Primary Source Agency for settlement. On the same day, a Kalshi employee opened a new account using a Kalshi email address. According to the complaint, that person is a lawyer whose role covers defining market rules and ensuring consistent resolutions.

FlightAware learned of all this when reporters called for comment. It cancelled Kalshi's account and sent a cease-and-desist letter the following day, and on July 16 amended its terms of use and license agreement to expressly prohibit use in connection with betting, gambling, prediction markets and event contracts. On July 17, Kalshi responded that its references constituted nominative fair use.

The shape of the dispute becomes clear here. What FlightAware emphasized in its complaint, as much as the unauthorized data use, was the reputational damage from having its name and registered trademark displayed as the basis for settling wagers. After the media coverage, users assumed FlightAware was involved in the markets, and posts announcing a switch to competing services circulated widely. The moment Kalshi stopped displaying the name, the lawsuit disappeared. The central question of whether the data could lawfully be used remains undecided.

The complaint also notes that Kalshi's own CFTC self-certification identified US Department of Transportation Bureau of Transportation Statistics on-time reporting data as an alternative source if FlightAware data were unavailable. A substitute was technically available. Kalshi nonetheless displayed the FlightAware name, because that name functions as shorthand for accurate and neutral aviation information.

A Fast-Growing Market and the Structural Gap at Settlement

Kalshi's scale is no longer marginal. Reporting cited in the complaint puts its share of the US prediction market at roughly 90 percent, with about two million monthly users. In May 2026 the company raised one billion US dollars (roughly 160 billion yen at 160 yen to the dollar) at a valuation of 22 billion dollars (roughly 3.52 trillion yen). Annualized trading volume was reported at 178 billion dollars (roughly 28.48 trillion yen), more than triple the level six months earlier, with annualized revenue exceeding 1.5 billion dollars (roughly 240 billion yen). More recent reporting describes talks to raise at a valuation near 40 billion dollars.

Cases involving manipulation of settlement sources have accumulated alongside that growth. The complaint lists several. In April 2026, when Polymarket offered a market on the maximum daily temperature in Paris, the weather station at Charles de Gaulle Airport recorded a brief unexplained spike that did not appear at nearby stations, shortly after an anonymous trader placed long-shot bets against the consensus outcome, turning under 120 dollars into more than 21,000. Météo-France opened an investigation and the matter was referred to French police. A White House teleprompter operator won approximately 100,000 dollars betting on presidential speech content, and streams were removed from a music service after suspicious activity around a daily chart market.

What these share is that the target of attack is not the underlying event but the data that records it. A prediction market places a cash value not only on knowing an outcome but on being able to reach the mechanism that registers it.

The decisive point is that the CFTC self-certification process does not require the consent of the entity being designated. An exchange can unilaterally name a third party as Primary Source Agency, and that party has no means of knowing. FlightAware learning of the markets through a reporter was not an accident but a consequence of how the framework is built. A data provider can be installed as the settlement authority for a financial contract without knowing it, bearing only the reputational exposure to that market's outcomes.

What This Means for Onchain Finance

This structure is not unique to prediction markets. Valuation of tokenized assets, clearing of derivatives, mark-to-market of stablecoin collateral: every contract in onchain finance depends on authoritative external data for settlement. The mechanism is what the industry calls an oracle.

What this episode demonstrates is how legally and economically fragile the position of that oracle's supplier is. Rights in data itself receive limited copyright protection, leaving providers reliant on terms of use as contract. Litigating a breach costs time and money while the markets keep running. Trademark, by contrast, bites hard. FlightAware led with trademark, and Kalshi extinguished the dispute immediately by ceasing to display the name. The data continued to flow and only the name vanished.

The question worth asking is whether anyone is being paid for the status of settlement authority. Kalshi earns a fee on every transaction. The supplier of the data that makes those settlements possible receives nothing. That asymmetry can repeat across onchain finance well beyond prediction markets.

Business Development Insights

  1. Data providers should design pricing that explicitly separates settlement use. FlightAware's existing terms prohibited commercial use but did not name prediction markets. The company's subsequent amendment adding an express prohibition on betting, prediction markets and event contracts was aimed at closing that ambiguity. The alternative, however, was to license such use for a fee rather than prohibit it. Data used as the settlement basis for a financial contract carries economic value on a different order from data used for viewing. Separating viewing, analysis and settlement use across both the terms and the rate card is the first line of defense for any company holding data assets, and simultaneously a new revenue line.
  2. Trademark works faster than data rights. This dispute effectively resolved when Kalshi replaced the company name with "Primary Source Agency." The legality of the data use remains unlitigated, and the conflict closed on non-use of the mark alone. The implication for data owners is that controlling whether your brand is displayed as a settlement basis can be a more practical and far quicker lever than trying to stop the data use itself. License agreements should include a standalone clause prohibiting display of the licensor's name or marks as a settlement source.
  3. Designers of onchain finance should build oracle consent and compensation into the initial architecture. The institutional gap here was a self-certification process requiring no consent from the party being designated. For tokenized assets and for the onchain transactions now under study in Japan, how the reference source for valuation or event determination is designated, and what contract exists with that provider, is a question that tends to be deferred. But where settlement depends on external data, the provider's withdrawal or objection is itself a market stoppage risk. Building three elements into the initial design — a supply agreement for reference data, a documented switchover procedure to an alternative source, and compensation to the provider — costs far less than the disputes that follow their absence.

Sources

Disclaimer

This report has been prepared solely for informational purposes regarding crypto assets and related markets, and is not intended to recommend, solicit, or offer the purchase, sale, holding, or any other transaction of any specific crypto asset. It does not constitute investment advice, investment solicitation, or the sale or intermediation of financial products as defined under the Financial Instruments and Exchange Act or any other applicable laws and regulations, nor does it constitute tax, legal, or accounting advice.

The information contained in this report is based on sources believed to be reliable at the time of preparation; however, we make no representation or warranty, express or implied, as to its accuracy, completeness, timeliness, or usefulness. Crypto assets are subject to significant price volatility and may result in the loss of principal or other financial losses. Any investment decision shall be made solely at the user's own discretion and responsibility, and we accept no liability whatsoever for any damages arising out of or in connection with the use of this report.

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