Kalshi tops $4.4 billion, Polymarket rebounds: October data highlights prediction markets’ momentum

Prediction markets just moved into a different league. In October 2025, event trading on platforms such as Kalshi and Polymarket confirmed its status as a high-volume vertical in its own right, reaching record-breaking volumes.

Both operators closed the month with record activity and combined volumes in the high single-digit billions, driven above all by sports-style contracts that resemble online sports betting. Recent datasets place Kalshi's October notional volume at around $4.4 billion and Polymarket's at about $3.0 billion, with sector-wide estimates between $7.4 and $8.7 billion when smaller operators are included.

Record numbers for the two platforms

Kalshi, which operates under U.S. Commodity Futures Trading Commission oversight, settles in dollars through banking rails, which allows it to present its instruments as event-based derivatives rather than gambling products. 

That framing shapes its user base: a mix of retail traders who already buy stocks and options, alongside more speculative profiles looking for direct exposure to elections, macro releases, or high-profile games.

The $4.4 billion figure in a single month suggests that event contracts are no longer a marginal add-on inside trading apps, but a line of business that matters on its own. For brokers and fintechs, prediction markets are starting to look less like a novelty and more like another standardized product that can drive engagement and fee revenue.

Polymarket leans on crypto-native infrastructure. Contracts are traded and settled on-chain, using stablecoins as the unit of account and non-custodial wallets as the main access point.

The October rebound to roughly 3.0 billion dollars in volume comes alongside an all-time high in monthly active traders and more than 38,000 new markets created in a single month, according to analytics compiled in the last few days.

That combination of liquidity and breadth is central to its appeal: users can trade on elections, macro data, meme culture, token events, sports, and niche Web3 narratives from the same interface.

Sports-style markets move to center stage

October not only changed the size of prediction markets; it also shifted what drives them. On both platforms, sports-linked contracts moved closer to the center of the action.

On Kalshi, internal breakdowns and public dashboards show weeks in which sports volume clearly outpaces political volume, with stretches where markets on game results, total points, and player performance generate flows that previously were only seen around major elections.

Polymarket shows a similar pattern, even if the mix remains more diversified. Sports markets gained weight alongside political contracts and crypto-related themes, helping to push market creation to record levels. From a product perspective, many of these contracts mirror familiar sportsbook structures: moneyline-style outcomes, over/unders, futures on season winners or awards, and player-linked milestones.

Still, politics remains a key focus. The New York mayoral election was the top political market, with Kalshi reporting over $71 billion in volume and Polymarket recording $365 million.

Distribution, tokens, and the race for users

The October record also highlights the different levers each platform is using to scale.

Kalshi's main engine is distribution. By integrating into a major U.S. retail trading app, its event contracts now appear on the same screen as equities, ETFs, and options. For a user who already trades financial instruments, adding a small position on an election result, a policy decision, or a key game is a relatively small shift in behavior.

This brokerage presence goes a long way toward explaining why Kalshi has pulled ahead on monthly volume: prediction markets become available to millions of existing trading accounts without requiring a separate onboarding process or a new funding flow.

Polymarket's incentives look more like Web3. Confirmation of a native token and a future airdrop acted as a catalyst for liquidity and repeat activity, as traders tried to maximize their on-chain footprint ahead of any distribution. That token narrative, combined with expectations of a formal U.S. relaunch under a clearer compliance framework, after an earlier settlement with regulators, forced the platform to restrict access.

The result is the steepest growth curve in users and new markets among the major prediction venues, driven as much by community dynamics and crypto culture as by pure product appeal.

Regulation and emerging competitive pressure

Regulation remains the big variable that can redraw the map.

Kalshi operates on the basis of explicit approvals and contract categories, but every new frontier it approaches – especially sports or politically sensitive outcomes – raises questions about where to draw the line between permissible derivatives and betting.

Shifts in how regulators and courts interpret those boundaries, or political pushback against certain types of contracts, could alter what can be listed or how the product is marketed, even if the core structure remains intact.

Kalshi is already facing pushback from gaming regulators in several states, with differing outcomes across jurisdictions. The company previously obtained injunctions in Nevada and New Jersey, allowing it to continue offering its contracts. In contrast, the US District Court for the District of Maryland denied a similar injunction in July, though the state agreed not to enforce its ban until Kalshi’s appeal is heard.

Polymarket faces a dual challenge: it has to show that a fully on-chain venue can comply with U.S. requirements while keeping its core advantages of global liquidity, open access, and transparent settlement. A successful return to the U.S. market would be a powerful signal for the broader sector; a setback could reinforce the perception that decentralized prediction platforms will remain largely offshore and informal.

In late September, the company confirmed that it will release a native token and conduct an airdrop once it completes its US relaunch. The rollout will be enabled through its newly acquired CFTC-regulated exchange, QCX. It is believed the US version of the platform could launch at any time.

At the same time, new entrants are circling. Large crypto exchanges and financial platforms are openly exploring prediction markets as a future product line, positioning themselves to go head-to-head with the current leaders. If those plans materialize, Kalshi and Polymarket will face competition not just for users, but also for regulatory goodwill and for the best distribution deals with brokers, wallets, and app ecosystems.

Strategic implications for sportsbooks and the wider betting ecosystem

For sportsbooks, October's numbers are more than a passing headline. They signal that prediction markets are consolidating as a stable channel to monetize interest in sports and real-world events, rather than as a tool that only comes into focus during election cycles.

In the short term, they compete directly for user time and wallet share. A bettor who splits their activity between a licensed sportsbook and a prediction platform is diversifying across two regulatory regimes and two risk models, but driven by the same motivations: entertainment, information, and the opportunity to profit from being right.

The longer-term scenarios range from coexistence to convergence. Last month, DraftKings announced the acquisition of Railbird Technologies Inc. and its subsidiary Railbird Exchange, marking its official entry into the prediction markets sector.

The acquisition follows similar moves by competitors. FanDuel announced a partnership with CME Group in August to form a joint venture seeking futures commission merchant (FCM) status, focusing on short-term markets tied to commodities and financial indices.

Meanwhile, Underdog Fantasy has launched a prediction market product through a partnership with Crypto.com, offering sports-based event contracts in states without legalized sports betting.