Combined monthly trading volume on Kalshi and Polymarket rose from under $5 billion in September 2025 to $24 billion by April 2026, a roughly 5x increase in seven months. Lifetime combined volume crossed $150 billion in April. On June 23, Cboe Global Markets launched Cboe Predicts, its first pred...
"Following the success of SPX 0DTE options, we have seen continued customer demand for shorter-dated, outcome-based trading, creating a natural extension for Cboe to introduce XSP binary options." — JJ Kinahan, Head of Retail Expansion and Alternative Investment Products, Cboe Global Markets
Combined monthly trading volume on Kalshi and Polymarket rose from under $5 billion in September 2025 to $24 billion by April 2026, a roughly 5x increase in seven months. Lifetime combined volume crossed $150 billion in April. On June 23, Cboe Global Markets launched Cboe Predicts, its first prediction-market product since discontinuing S&P 500 binary options in 2017, directly targeting the retail demand that crypto-native platforms created.
The launch landed on the same day the Commodity Futures Trading Commission filed its ninth state preemption suit — against Kentucky — in an expanding jurisdictional war over whether prediction markets are federally regulated derivatives or state-level gambling. With a 267-page CFTC proposed rulemaking published June 10 and a comment period running through late August, the regulatory architecture for this $150 billion-plus market segment remains unresolved.
This report examines the collision of three forces: institutional incumbents entering the prediction market, explosive growth in crypto-native platforms, and the federal-state regulatory fracture that will determine which entities can operate and on what terms.
The prediction market sector has undergone a structural transformation over the past 18 months. According to Pew Research Center data published May 27, 2026, combined monthly global trading volume on Kalshi and Polymarket rose from under $5 billion in September 2025 to approximately $24 billion in April 2026. Monthly volume peaked near $25.7 billion in March 2026. The sector has grown more than 17-fold from mid-2024, when total monthly taker volume sat below $500 million.
The daily volume record was set on June 10, 2026, when Polymarket closed at $818.4 million in spot volume. That day coincided with the FIFA World Cup opening and the SpaceX IPO pricing at $135 per share, according to Cryptopolitan. Open interest across prediction markets reached $1.48 billion in the week ending June 15, a second consecutive all-time high, per a16z Crypto.
The growth is not purely retail-driven. According to Yahoo Finance reporting from April 2026, Kalshi's institutional trading volume grew 800% over six months. The platform raised $1 billion led by Coatue Management at a $22 billion valuation and reported annualized revenue exceeding $1.5 billion.
Monthly unique wallets on Polymarket nearly tripled to 840,000 in the six months leading to February 2026, according to TRM Labs. However, growth showed signs of deceleration in April, with Polymarket active traders declining to 643,000 from 733,000 in March.
On June 23, 2026, Cboe Global Markets launched Cboe Predicts, reintroducing binary options on the Mini-S&P 500 Index (XSP) under the tickers XSPBW and XSPBX. The last Cboe binary option contract had expired in 2017.
The product is sized at 1/10th of the SPX to serve retail traders. Contracts pay $100 if the index settles at or above a specified level, and $0 otherwise. A "plus" variant uses vertical spread structures to provide partial payouts as the index moves, rather than the traditional all-or-nothing binary outcome.
Distribution began immediately on Interactive Brokers, with Charles Schwab — which manages $11.8 trillion across 47.2 million accounts — expected to add access later in 2026. Rob Hocking, Cboe's Global Head of Derivatives, stated the goal is to "help set a higher standard for market integrity, product design and investor protection."
The strategic logic is straightforward. Cboe's same-day S&P 500 options (0DTE) already represent approximately 30% of U.S. options volume, according to CoinDesk. Binary options are a simplification of the same directional bet. The contracts clear through the Options Clearing Corporation under SEC oversight — a deliberate distinction from the CFTC-regulated environment in which Kalshi and Polymarket operate.
Cboe explicitly avoided political, sports, and entertainment contracts. This is not incidental. Financial-benchmark-only markets sidestep the regulatory conflicts that have engulfed the category.
The two dominant platforms have diverged in structure and user base.
Kalshi is a U.S.-registered designated contract market (DCM) under full CFTC oversight. In May 2026, it processed $16.81 billion in volume, compared to Polymarket's $7.08 billion, according to Cryptopolitan. Sports contracts account for 80% of Kalshi's total volume since July 2024. The platform's annualized trading volume stands at $178 billion, having tripled over six months.
Polymarket is crypto-native, built on Polygon, and operates through two entities: Polymarket International (the larger platform, technically closed to U.S. persons) and Polymarket US (newly CFTC-regulated). In April 2026, Polymarket US saw $1.3 billion in trading volume versus $9 billion on Polymarket International. According to Stanford Law School analysis published April 30, former SEC Commissioner Joseph Grundfest noted that Polymarket International "does not apply U.S.-style anti-money laundering or know-your-customer rules" and that "Americans use VPNs to access it."
Intercontinental Exchange (ICE) invested $2 billion in Polymarket in October 2025 and completed an additional $600 million investment on March 27, 2026, signaling institutional conviction in the crypto-native platform's market position.
TRM Labs data from February 2026 shows the user composition: mid-frequency traders (11–1,000 trades) account for 44.7% of activity and $869 million in volume, while high-frequency market makers (10,000+ trades) represent 35.2% of activity and $774 million in volume. Single-trade users contribute less than 0.2% of volume.
On June 10, 2026, the CFTC published a Notice of Proposed Rulemaking (RIN 3038-AF65), "Prediction Markets; Public Interest Determinations," proposing amendments to 17 C.F.R., Part 40 (Rule 40.11). The 267-page document constitutes the first formal federal regulatory framework for prediction markets.
The proposed rule would permit event contracts tied to macro-level sports outcomes: team wins, playoff advancement, final scores, point differentials, and season-long statistical performance. It would prohibit contracts on individual plays, single pitches, single shots, fouls, physical altercations during games, injuries, officiating decisions, and pre-collegiate events.
The Commission proposes a three-step sequential analysis: (1) whether the contract involves an excluded commodity, (2) whether it "involves" enumerated prohibited activities (terrorism, assassination, war, unlawful activity, or gaming), and (3) whether the contract is contrary to the public interest.
The American Gaming Association, led by president Bill Miller, opposes the framework. States and tribal gaming interests estimate prediction markets divert over $1 billion in tax revenue annually from regulated gambling. In Congress, the Curtis-Schiff "Prediction Markets Are Gambling Act" has been introduced to reclassify these contracts entirely.
The comment period closes in late August 2026. The final rule, whenever published, will determine whether sports-linked event contracts can legally exist on CFTC-regulated platforms — or whether Congress intervenes to recategorize them.
The CFTC's June 23 suit against Kentucky marked its ninth state preemption action. Prior suits targeted Wisconsin, Illinois, Arizona, Connecticut, New York, New Mexico, Minnesota, and Rhode Island. The agency asserts that the Commodity Exchange Act grants it exclusive jurisdiction over event contracts traded on designated contract markets, preempting state gambling laws.
Kentucky had taken aggressive action: filing civil enforcement cases against Kalshi and Polymarket in state court, seeking monetary penalties, and imposing a 14.25% excise tax on prediction-market transaction fees. On June 12, a coalition including Kalshi, Crypto.com, Polymarket, and Robinhood sued Kentucky over the tax.
The legal landscape is fractured. In the Sixth Circuit (Kentucky, Ohio, Tennessee, Michigan), two district court judges have preliminarily sided with state regulators while one has sided with the platforms. A circuit court split is widely anticipated, and the issue is expected to reach the U.S. Supreme Court.
Six prediction-market ETFs from Roundhill Investments, GraniteShares, and Bitwise faced delayed launches expected in early May 2026. The SEC requested additional information on product mechanics and investor disclosures, according to Yahoo Finance.
The rapid scaling has surfaced integrity risks. TRM Labs documented a case where four coordinated wallets turned approximately $40,000 into $872,000 on Iran strike contracts by entering markets priced at $0.10–$0.80 per share, using an identical funding source within a narrow time window, and redeeming at $1.00 upon resolution.
In a separate case reported by Stanford Law School, a U.S. Special Forces soldier placed bets using classified information about Venezuelan leader Nicolas Maduro's removal, earning over $400,000 before arrest.
Kalshi responded with new safeguards including default Face ID verification, selfie verification for higher-risk accounts, enhanced two-factor authentication, account-sharing monitoring, and deposit-limit recommendations. The platform also announced insider trading restrictions jointly with Polymarket on March 23, 2026.
The prediction market sector has reached a scale where its regulatory classification carries material economic consequences. At $24 billion in monthly volume, the question of whether these instruments are CFTC-regulated derivatives or state-regulated gambling involves real money — over $1 billion in estimated annual tax revenue according to state and tribal gaming interests, and $1.5 billion in annualized revenue for Kalshi alone.
Cboe's entrance recasts the competitive landscape. A legacy exchange with SEC-regulated clearing infrastructure offering simplified binary options on financial benchmarks does not need the CFTC sports-contract ruling to proceed. Its products exist in a cleaner regulatory zone. The implication: crypto-native platforms built on sports volume face a regulatory risk that incumbents with financial-only products do not.
The CFTC rulemaking, nine state lawsuits, congressional legislation, and ETF delays form an interlocking set of unresolved questions. Until the comment period closes, the final rule publishes, and courts resolve the preemption question, the $150 billion prediction market operates in a regulatory interim where the rules of operation could change materially in any direction.