US Senators' Bill Targets Prediction Markets, Igniting Rally in UK Gambling Stocks

The Spark on March 23, 2026

On March 23, 2026, shares of UK-listed gambling companies leaped forward after bipartisan legislation hit the US Senate floor; Senators Adam Schiff, a Democrat from California, and John Curtis, a Republican from Utah, introduced a bill to bar CFTC-regulated prediction market platforms such as Kalshi and Polymarket from offering sports betting contracts, a move that traders interpreted as a shield for established sportsbooks. Flutter Entertainment, the parent of FanDuel, surged 7.6% on the London Stock Exchange, while Entain, which owns Ladbrokes and holds a stake in BetMGM, climbed 6.4% in the same session; the reaction unfolded swiftly as markets digested the bill's potential to curb upstarts encroaching on traditional betting turf.

What's interesting here is how quickly the news rippled across the Atlantic, boosting confidence among investors who track the £multi-billion gambling sector; data from the Investing.com report captured the intraday gains, with Flutter's shares hitting a high not seen in recent weeks and Entain following suit amid broader FTSE gains. And yet, the surge stood out because it tied directly to regulatory shifts in the US, where sports betting has exploded since the 2018 Supreme Court decision overturning PASPA.

Details of the Bipartisan Legislation

Senators Schiff and Curtis framed their bill as a necessary step to protect licensed sports betting operators from unregulated competition; prediction markets like Kalshi, overseen by the Commodity Futures Trading Commission (CFTC), have ballooned in sports-related trading volume, with Kalshi reporting that sports bets accounted for roughly 90% of its activity, all without the state-level gambling licenses required of traditional platforms. The legislation targets these CFTC-regulated entities specifically, aiming to prohibit contracts on sports outcomes that mimic betting lines offered by FanDuel, DraftKings, or BetMGM.

Observers note that the bill's language draws a clear line between event contracts—prediction market staples—and outright gambling; under current CFTC rules, platforms can trade yes/no outcomes on elections, weather, or economics, but sports have become a gray area that's drawn scrutiny, especially as volumes rival those of legacy sportsbooks. But here's the thing: Kalshi and Polymarket operate nationwide without state-by-state approvals, sidestepping the patchwork of regulations that traditional operators navigate across 38 states plus DC where sports betting thrives legally.

Figures from Kalshi underscore the stakes; in recent months, sports events like NFL games and college basketball finals drove millions in trading volume, pulling users who might otherwise wager on apps like FanDuel. The CFTC's oversight reports highlight how these platforms have scaled rapidly since gaining approval for certain contracts, yet lawmakers argue this undercuts revenue for states reliant on gambling taxes, which topped $5 billion in 2025 per American Gaming Association data.

Spotlight on the Stock Surge

Flutter Entertainment led the charge with its 7.6% jump, pushing its market cap higher in a session where volume spiked noticeably; as FanDuel's owner, the Irish-domiciled firm dominates US sports betting with a reported 40%+ market share in key states, so any threat to rivals like prediction markets plays right into its strengths. Entain trailed close behind at 6.4%, buoyed by its BetMGM joint venture with MGM Resorts, which commands a solid slice of the US online and retail betting pie; together, these gains added hundreds of millions to their combined valuations in hours.

Trading data reveals the momentum built through the afternoon London session, with Flutter shares crossing above recent resistance levels while Entain benefited from broader sector tailwinds; investors piled in, citing the bill's bipartisan backing as a signal of real momentum, unlike partisan efforts that often fizzle. Short interest in both stocks dipped marginally that day, as per London exchange records, reflecting bets on sustained upside if the legislation advances.

• Flutter (LSE: FLTR): +7.6%, closing near 52-week highs after the news.
• Entain (LSE: ENT): +6.4%, rebounding from prior dips tied to US operational costs.

Smaller peers like 888 Holdings and Evoke also edged up, though less dramatically, showing the rally's sector-wide echo; that's where the rubber meets the road for analysts tracking cross-border flows in gambling equities.

Prediction Markets vs. Traditional Sportsbooks

Kalshi and Polymarket represent a new breed in the betting world, trading binary contracts on future events through a futures-like exchange model; users buy "yes" or "no" shares on outcomes—say, will teh Kansas City Chiefs cover the spread?—with prices reflecting crowd-sourced probabilities that update in real-time. Traditional sportsbooks, by contrast, set odds via expert models and take a vig on every bet, requiring hefty licenses and compliance in each state.

Turns out, this distinction has fueled tensions; Kalshi's sports volumes hit 90% of total trades, per company disclosures, drawing bettors with low fees and nationwide access, while platforms like Polymarket—crypto-adjacent and offshore in some views—have mirrored that growth on events from Super Bowls to March Madness. Experts who've studied this space point out how prediction markets offer tighter lines and no house edge beyond fees, siphoning action from FanDuel's $multi-billion handle.

One case stands out: during the 2025 NFL playoffs, Kalshi reported over $100 million in sports contract volume, rivaling mid-tier sportsbooks; without state taxes or licensing fees, these platforms undercut costs, prompting calls for parity from groups like the American Gaming Association, though the bill focuses squarely on CFTC jurisdiction. People in the industry often discover that regulatory arbitrage like this reshapes markets overnight, and March 23 proved no exception.

Company Backstories and US Footprint

Flutter Entertainment traces its roots to Paddy Power and Betfair mergers, evolving into a transatlantic powerhouse with FanDuel as its US crown jewel; post-2018 legalization, FanDuel rocketed to the top spot, handling billions in wagers annually across apps and retail partners. Entain, born from GVC Holdings' acquisition of Ladbrokes Coral, expanded stateside via BetMGM, a 50/50 venture launched in 2018 that now operates in 20+ states with iGaming in places like New Jersey and Michigan.

Both firms have poured billions into US marketing and tech, navigating taxes up to 51% in some states while complying with age checks, geofencing, and responsible gaming mandates; their London listings attract global capital, making them sensitive barometers for regulatory winds. Data indicates Flutter generated over 40% of its revenue from the US in 2025, with Entain close behind via BetMGM's growth, so threats to newcomers like Kalshi hit close to home.

It's noteworthy that prior CFTC approvals for Kalshi's sports contracts in 2024 sparked early stock wobbles for these giants, yet the bipartisan bill reversed that narrative on March 23; observers who've tracked the sector know how such events can sustain multi-day rallies if committees take up the measure.

Broader Market Ripples and What's Next

The FTSE gambling index rose over 5% that day, with Flutter and Entain as top performers, signaling investor bets on a cleaner competitive landscape; US futures hinted at pre-market gains for peers like DraftKings and Rush Street Interactive the following day, underscoring the story's transatlantic pull. Prediction market execs pushed back, arguing their model aids price discovery without traditional gambling risks, but lawmakers emphasized consumer protections and tax equity.

Now, the bill heads to committee, where amendments could refine its scope—perhaps carving out non-sports events—yet its introduction alone shifted sentiment; states like New Jersey and Pennsylvania, heavy on gambling revenue, stand to gain if unlicensed volumes dry up. Those who've followed CFTC vs. state regulators see this as the latest chapter in a tug-of-war that's defined the post-PASPA era.

Short-term, analysts project stabilized handles for traditional operators if the ban sticks; long-term, it could spur innovation in licensed prediction-style products from FanDuel or BetMGM themselves. Either way, March 23 marked a pivot point where Washington’s hand tilted the scales toward London-listed incumbents.

Conclusion

Senators Schiff and Curtis' bill crystallized a clash between prediction markets and sportsbooks, driving a sharp rally in UK gambling stocks on March 23, 2026; Flutter's 7.6% gain and Entain's 6.4% lift reflected market conviction that regulatory clarity favors licensed giants. As Kalshi's 90% sports dominance faces curbs, traditional platforms eye recaptured volume, taxes preserved, and competition leveled; the London exchange's reaction encapsulated how US policy moves echo globally in this high-stakes arena, with committees now holding the next cards.