Bellingcat: World Cup fans bet billions on Polymarket and Kalshi
Bellingcat published an article on July 30, 2026 examining World Cup prediction market activity, noting that fans have bet billions through these platforms. The piece highlights that crypto-based Polymarket provides more information about individual trading accounts than its American rival Kalshi. A separate Reddit post by a retired sports trader discussed algorithmic trading on Polymarket during the tournament, referencing custom API execution and liquidity considerations but offering no concrete performance data.
The transparency gap Bellingcat identifies reverses the usual regulatory story. Polymarket, often framed as the more opaque crypto venue, now exposes more account-level data than CFTC-registered Kalshi. That matters because Congress is weighing a bipartisan Senate bill to ban sports event contracts on CFTC-registered platforms, and lawmakers are hungry for evidence that platforms can police themselves.
Kalshi's lighter disclosure gives critics ammunition: if the regulated American exchange hides more than its crypto rival, federal self-regulation claims weaken. Both platforms face identical ban risk. The one that builds credible surveillance first may deflect legislation or shape its final form. The other becomes the example that justifies the ban.