The milestone, reported by The Block on May 1, marks roughly a 6.5x year-on-year increase for the prediction market sector overall. In April alone, Kalshi processed approximately $13.4 billion, capturing 52% of measured market share, while Polymarket handled $8.5 billion for a 33% share. For context, both platforms combined for only around $40 billion across all of 2025, according to Phemex.

The sector's strongest week ran from April 20 to 26, when all tracked platforms together reached $7.1 billion in volume. DeFiRate puts the combined figure for Kalshi and Polymarket specifically at $5.9 billion across the same period. Kalshi alone posted $3.91 billion, a 27.8% week-on-week gain, while Polymarket recorded $1.96 billion. Data from DeFiRate shows total open interest across both platforms hit $1.1 billion at the peak, split between Kalshi at $610.8 million and Polymarket at $509.5 million. The primary catalysts were Iran ceasefire negotiations and volatility tied to the prospect of a Strait of Hormuz oil blockade, events that carry significant downstream economic consequences for energy-importing regions.

Kalshi's growth is partly attributable to parlay and exotic products, which allow users to combine multiple event outcomes into a single position. In the April 20 week, exotic contracts on Kalshi generated $412.5 million in volume, roughly 10.6% of Kalshi's total activity for that period and nearly three times the February level. Sports contracts still account for 74.3% of Kalshi's total activity overall. Polymarket carries a more distributed mix: sports at 46%, crypto markets at 22%, and politics at 15%.

A notable third-place finisher this month was Limitless, which recorded $1.4 billion in April volume, a 177% surge from the prior period and its first appearance in the top three. The sector also includes several other challengers worth noting: Predict.fun recorded $1.3 billion and Opinion Labs posted $636.2 million in April, reflecting a competitive field that extends well beyond the two dominant platforms.

The regulatory environment surrounding both platforms intensified in April. On April 30, the US Senate unanimously voted to ban senators from trading on prediction markets. Kalshi CEO Tarek Mansour responded by framing the vote as a positive signal: "Kalshi already proactively blocks members of congress [sic] and enforces against insider trading. This is a great step to increase trust in our markets by making it an industry standard." Mansour has also publicly called for a federal consumer protection framework governing the sector, arguing that a state-by-state regulatory approach "has failed."

Mansour has separately called on federal authorities to pursue bad actors, stating publicly that he expects the Department of Justice to prosecute insider trading cases on prediction market platforms.

Congressional Democrats, led by Senator Jeff Merkley, also pressured the CFTC (the Commodity Futures Trading Commission, the primary US derivatives regulator) to address what they called "the rapid erosion of integrity" in the sector, citing concerns about insider trading and prohibitions on contracts tied to elections, war, sports, and government actions. In direct response to those integrity concerns, Polymarket announced a partnership with blockchain analytics firm Chainalysis to integrate anomaly detection and insider-activity identification capabilities into its platform.

At the state level, Texas moved to impose restrictions on prediction market activity, while Wisconsin became the fifth state sued by the CFTC, which argues it holds exclusive federal jurisdiction over event contracts. The commission has framed that jurisdictional claim in part around a distinction between sports betting, which it characterises as entertainment, and event contracts, which it treats as financial hedging instruments.

Outside the US, the story looks different.

Kalshi is a CFTC-regulated, US-centric exchange requiring American identity verification. Polymarket, by contrast, operates as a decentralized application on the Polygon blockchain and allows access through any compatible crypto wallet, such as MetaMask, using USDC stablecoins. The platform is accessible in more than 160 countries but is blocked in the US, UK, and several EU jurisdictions. Users in India, Pakistan, Nigeria, Kenya, Ghana, and South Africa are not on Polymarket's block list.

That permissionless structure matters: approximately 840,000 unique wallets were active on Polymarket monthly in early 2026, and Polygon surpassed Solana as the most active USDC chain by transaction count, logging 28 million weekly transactions.

The geopolitical dimension is particularly visible in South Asia right now. Following the Pahalgam attack on April 22 and the subsequent India-Pakistan diplomatic crisis, Polymarket's 110-plus active India-Pakistan prediction markets accumulated over $11.2 million in total volume. Users are trading on outcomes including war declarations, ceasefire timelines, and diplomatic resolutions.

For users across the region who may already hold USDC on Polygon as a hedge against local currency volatility, the barrier to participating in these markets is low: no broker account, no fiat conversion, just an on-chain wallet and a stablecoin balance. Polymarket's April 28 infrastructure upgrade, which replaced USDC.e with a new settlement token called pUSD (a 1:1 USDC-backed ERC-20 token on Polygon), is designed to smooth this process further.

For African users, the structural case is similar. Dollar-denominated exposure on decentralized infrastructure is already a common DeFi use case in Nigeria and South Africa, where local currency volatility makes stablecoin-denominated products attractive. Polymarket draws 57.98% of its global traffic from the broad geographic category that encompasses these markets, reflecting demand well beyond Western jurisdictions. Prediction markets covering commodity prices, geopolitical outcomes, and crypto assets extend that DeFi framework into new territory. The outcome of the ongoing CFTC-versus-states jurisdictional dispute may also set a regulatory template that shapes how authorities in India, Nigeria, Kenya, and other high-growth markets eventually classify these products.

The competitive picture is also shifting. Gemini recently secured a CFTC Derivatives Clearing Organization (DCO) license and is preparing to enter prediction markets, while Hyperliquid has signaled its own move into the space.

Kalshi raised $1 billion in March 2026 at a $22 billion valuation, in a round led by Coatue Management. Andreessen Horowitz, Sequoia Capital, Paradigm, and Ark Invest are among the platform's prior investors. Polymarket was valued at $9 billion following a $2 billion investment from Intercontinental Exchange in October 2025. With institutional capital accumulating and a regulatory framework still being contested across multiple US jurisdictions, the structure of the global prediction market industry is unlikely to look the same by the end of 2026.