Two accounts on Polymarket have drawn scrutiny after earning about $37,000 from bets tied to unusual temperature readings in Paris.
The trades were based on data from a weather station at Charles de Gaulle Airport, where sudden temperature spikes determined the outcome of prediction markets on April 6 and 15.
“Such temperature variations seem very unlikely, especially on these two dates, and over such a short period,”
Said Ruben Hallali, adding:
“We can imagine that an individual with a good understanding of how the sensors work intervened, resulting in temperatures rising by two degrees at the right time, to validate a bet.”
One winning account, less than 30 days old, profited more than $16,000 from the April 6 event, while another trade linked to a similar spike generated over $21,000.
Analysts from Bubblemaps said the spikes were not reflected at nearby weather stations and flagged suspicious trading patterns preceding the anomalies.
France’s national weather agency has filed a complaint with authorities, alleging possible tampering with automated data systems at the airport station.
The episode adds to growing concerns over manipulation and insider advantage in prediction markets, which are already under regulatory and legal scrutiny globally.