CHICAGO — Cardi B was part of Bad Bunny’s Super Bowl halftime show. What she did exactly, well, that turned into a perplexing question for two major prediction markets.

At least one Kalshi trader filed a complaint with the Commodity Futures Trading Commission over how the prediction market handled Sunday’s appearance by the Grammy-winning rapper. The result of a similar event contract on Polymarket also drew the ire of some users on that platform.

Prediction markets provide an opportunity to trade — or wager — on the result of future events. The markets are comprised of typically yes-or-no questions called event contracts, with the prices connected to what traders are willing to pay, which theoretically indicates the perceived probability of an event occurring.

The buy-in for each contract ranges from $0 to $1 each, reflecting a 0% to 100% chance of what traders think could happen.

More than $47.3 million was wagered on Kalshi’s market for “ Who will perform at the Big Game? ” A Polymarket contract had more than $10 million in volume.

Cardi B joined singers Karol G and Young Miko and actors Jessica Alba and Pedro Pascal on a starry front porch during the halftime spectacle. She danced to the music, but it was unclear whether she was singing along during the show, which included performances by Ricky Martin and Lady Gaga.

Due to “ambiguity over whether or not Cardi B’s attendance at the 2026 Super Bowl halftime show constituted a qualifying ‘performance,’” Kalshi cited one of its rules in settling the market at the last price before trading was paused: $0.74 for No holders and $0.26 for Yes holders. The platform returned all the money to its users.

Polymarket’s contract was resolved as Cardi B had performed, but the yes was disputed. A final decision on the contract is expected to be announced on Wednesday.

In the CFTC complaint — first reported by the Event Horizon newsletter and posted by Front Office Sports — the trader alleges that Kalshi violated the Commodity Exchange Act with how it resolved the Cardi B contract. The trader — a Yes holder — is seeking $3,700.

A CFTC spokesman declined comment on Wednesday.

The Super Bowl capped a big NFL season for prediction markets.

Kalshi reported a daily record high of more than $1 billion in total trading volume on the day of the game, an increase of more than 2,700% compared to last year’s Super Bowl. The season-long total for all Super Bowl winner futures was $828.6 million, up more than 2,000% from last year.

The increased activity on Sunday caused some deposit issues. Kalshi co-founder Luana Lopes Lara posted on X on Monday that the “traffic spike was way bigger than our most optimistic forecasts.” She said the platform had reimbursed processing fees on the effected deposits and added credits to users who experienced delays.

Robinhood Markets highlighted the strength of its prediction markets when it announced its financial results for the fourth quarter and full 2025 on Tuesday.

“I think we are just at the beginning of a prediction market super cycle that could drive trillions in annual volume over time,” CEO Vlad Tenev said during an earnings call. “This year is going to be a big year. Olympics are going on right now. World Cup coming in the summer.”