TLDR
Try pricing a betting app in your head for a second. Now try pricing an exchange. Kalshi and Polymarket have spent the last year getting valued like the second thing, and the reason comes down to how each one actually moves money under the hood.
Polymarket’s core platform doesn’t hold your money. You fund a wallet with USDC, and when you buy a contract, that USDC and the resulting outcome token sit under your own private key, not in a Polymarket-controlled account. The trade itself executes through audited smart contracts running on Polygon, the same chain a lot of DeFi activity already lives on, which keeps gas costs down to a small fraction of a dollar per transaction instead of Ethereum mainnet pricing.
Kalshi works nothing like that. It’s a Designated Contract Market under CFTC oversight, and it holds customer cash the way a regulated brokerage does: in segregated, FDIC-insured bank accounts, including JPMorgan Chase and BNY Mellon. There’s no wallet, no gas fee, and no blockchain anywhere in the pipeline.
Neither setup is objectively safer. Kalshi’s model gives traders a federal regulator and an insured bank behind their cash, in exchange for trusting a centralized custodian. Polymarket’s model removes that custodian entirely, in exchange for traders taking on their own wallet security and smart-contract risk. It’s a real architectural fork, not a branding difference, and it’s the reason the two companies are starting to attract different flavors of institutional money.
According to prediction market data analytics platform PredictionHero, Kalshi posted $17.91B in notional volume in May 2026, its ninth straight monthly record. Polymarket posted $7.08B over the same month. Kalshi’s funding talks are reportedly closing in on a $40B valuation; Polymarket is fielding a round above $20B, up from roughly $8B when ICE first invested last October.
Look at who’s actually writing the checks. Kalshi’s March round pulled in Coatue, Sequoia, Andreessen Horowitz, Paradigm, Morgan Stanley, and ARK Invest. Polymarket’s cap table has Intercontinental Exchange, the company that owns the NYSE, alongside D.E. Shaw and G Squared. That’s not a normal startup investor list. It’s the list you’d expect on an actual exchange.
That framing matters because exchanges tend to end up one of three ways: acquired, folded into a regulated duopoly, or public. Kalshi has reportedly told investors it’s exploring an IPO for late 2026 or early 2027, complicated by the state lawsuits it’s fighting over whether its sports contracts count as gambling. Polymarket hasn’t put a date on anything, but a stock-exchange operator and two major quant shops aren’t usually along for a ride that ends quietly.
This is the part that should look familiar to anyone who follows crypto M&A rather than sports betting. Coinbase bought derivatives exchange Deribit for $2.9B last year, the largest deal in crypto history, specifically to get a derivatives book it didn’t want to build from scratch. Kraken answered a few months later, buying futures platform NinjaTrader for $1.5B rather than cede that ground.
The same pattern is now playing out around event contracts specifically. DraftKings bought exchange infrastructure firm Railbird and used it to launch its own in-house exchange, DKeX, this June, ending its reliance on CME Group and Crypto.com to clear contracts. Robinhood built a similar setup with Susquehanna, called Rothera. Coinbase bought a firm called The Clearing Company right after launching its own event contracts.
That leaves Kalshi and Polymarket in an interesting spot: both already own the regulated exchange layer that DraftKings and Robinhood just spent a year assembling piece by piece. Neither has the consumer distribution that DraftKings or Robinhood walked in with. Bernstein analysts have argued that makes both plausible acquisition targets, not just acquirers, which is a different read than the “one platform wins” framing most coverage defaults to.
Centralized and on-chain resolution both get tested eventually, and how each one handles a contested call is one of the more revealing differences between the two models.
Kalshi resolves markets internally, against its own published contract terms. That was tested in January 2026, when some traders holding winning NFL contracts were briefly paid only their original stake rather than the full settlement, after Kalshi said the underlying markets had closed early. Kalshi reversed the decision under user backlash and paid what was owed.
Polymarket routes disputes through UMA, where a proposer posts a bond with a proposed outcome and token holders can dispute and vote within a challenge window. That’s genuinely decentralized, and it’s still maturing in public: a roughly $79 million market on whether Ukrainian President Volodymyr Zelenskyy would wear a suit, and a March 2025 contract on a Trump-Ukraine minerals deal, both turned on how concentrated the winning vote happened to be. A separate, high-dollar 2026 dispute over a Strategy Bitcoin-sale market drew similar scrutiny.
Neither model has a clean record. Kalshi’s centralized structure means one company can make a mistake and correct it under public pressure, with a federal regulator as backstop. Polymarket’s token-voting structure removes that single point of failure, but a resolution can hinge on how concentrated a given vote turns out to be. For a full breakdown of how the fee structures, custody models, and dispute mechanics compare side by side, PredictionHero’s Kalshi vs. Polymarket comparison walks through all of it.
Neither, cleanly, and that’s arguably the more interesting story than picking a side. Kalshi has the volume lead and the clearer regulatory footing. Polymarket has the deeper global liquidity and a genuinely on-chain settlement layer that a lot of crypto-native capital finds structurally more interesting than a bank account, however well insured.
The two are being priced by very different types of investors for very different reasons, and the fact that both keep raising at higher numbers says more about how seriously infrastructure money is taking event contracts generally than it does about either company individually.
