The ‘Outsider Trading’ Problem
The article explores the rise of 'outsider trading' in prediction markets, where individuals manipulate real-world events to profit from wagers. It highlights incidents like tampering with weather sensors and potential insider access to information.
Why it matters
As prediction markets grow in popularity, they face significant integrity challenges regarding fraud, manipulation, and the ethical implications of betting on sensitive events.
A new, gonzo style of fraud could be an existential threat to prediction markets.
Illustration by Matteo Giuseppe Pani / The Atlantic July 20, 2026, 2:18 PM ET Share Save There are worse things you could do than drive to a Parisian airport and mess around with a temperature sensor on the airfield—for only a few minutes! But why do that at all?
To make money, maybe. This is the scheme that some mysterious person (or persons) reportedly carried out in April to win a bet on the prediction-market platform Polymarket, which allows people to wager on the highest temperature in Paris on any given day, not unlike weather derivatives . The popular version of the story says that the shadowy figure warmed the sensor with a hair dryer—a photo showing this turned out to be AI generated—but it could have been anything. A lighter, a hand warmer.
Get smarter about the news
Sign up free for a feed built around what you actually care about, Dive Deeper research on any story, and the full text of every article.
Create free accountAlready have an account? Sign in