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About Jackpot Bells
Beginning with the US presidential elections in November 2024, when prediction markets catapulted into mainstream culture, their rise has been undeniable. Kalshi and Polymarket have seen their valuations balloon to $40 billion and $21 billion, respectively, and the majority of the top US bookmakers have scrambled to expand into the prediction space in various forms, either by building their own exchanges, acquiring existing ones or engaging in market-making.
Commercial sports betting generated just under $17 billion in nationwide revenue in 2025, which is why Davenport asserts that the “stakes of this case are exceptionally high”. Kalshi and Polymarket alone posted more than $45 billion in trading volume, which is similar but not identical to betting revenue, in August. That was a 15% decline from July, although that drop is attributed to the conclusion of the Fifa World Cup tournament that month per Yahoo! Finance.
The American Gaming Association estimates that the exchanges have siphoned more than $1.3 billion in would-be tax revenue from states. One of the AGA’s primary spokespeople pin its fight against prediction markets is former New Jersey governor Chris Christie, who championed the PASPA case to the Supreme Court.
How to play Jackpot Bells
On Monday, the Gambling Regulators European Forum (GREF) announced a reshuffle of its board following the departure of two long-standing members and the appointment of two new officers.
GREF is a cooperative network bringing together national gambling regulators across Europe and beyond to facilitate dialogue, exchange information and share best practice on regulatory strategies.
Tim Miller, who resigned from the UK Gambling Commission earlier this year, has stepped down from the GREF board and has relinquished his role as treasurer.
How to play Jackpot Bells
Strip away the language of contracts, order books and event trading and Bernard Marantelli has a blunt description of what is happening inside US sports prediction markets. “Kalshi is a sportsbook that’s just not allowed to have an in-house risk team,” says the founder of White Swan Data, one of the specialist firms now making markets on prediction exchanges.
The difference is all about the risk function. A sportsbook employs traders to price bets and manage its exposure. An exchange provides an API through which firms compete to quote prices and supply liquidity.
“Here’s an API. Bernard and 88 other people can market-make all these request-for-quotes (RFQs),” Marantelli says. “Some people might come in and just do esports because they’re esports experts. Others do everything. Some focus on same-game parlays. But it’s a sportsbook.”
