Weekly trading volume in the non-sport categories across Kalshi and Polymarket reached a new high of $10 billion last week. Data from Artemis shows that this marked the sixth consecutive record week with Kalshi running away as clear leaders. Kalshi drew in $9.6 billion while Polymarket saw $344.2. It wasn’t always this one sided, though. In fact, this trend is quite recent. Up until early June, the stacked bars were actually even. Zoom out further to last year, the trend was actually reversed, with Polymarket firmly in the lead. Kalshi now controls 96% of this category, up from something close to a coin flip from just three months ago. Four Retail Apps Do the Selling for Kalshi Kalshi now has an impressive distribution channel across various retail platforms. Robinhood, Coinbase, Webull and Moomoo all carry its contracts to a massive user base that never went looking for Kalshi in the first place. Polymarket on the other still do not have these mainstream channels that cater to a much broader audience than just crypto natives. What those brokerages merchandise under the non-sports tab matters more than the partner count. Webull’s prediction markets page leads with Kalshi-powered hourly contracts on the S&P 500, Nasdaq, Bitcoin and Ethereum. Hourly Contracts Recycle the Same DepositAn hourly Bitcoin contract opens and settles inside sixty minutes. A trader closes one position and enters the next, and the same balance prints fresh notional every hour the market stays open. A contract resolving in November on a Fed decision locks that money up for weeks and reports once. Both land in the volume chart the same way, which means a dollar sitting in a Robinhood account generates far more reported activity than a dollar parked in a long-dated market. Multi-leg combos work on the same mechanic. A combo bundling several sports legs settles as a single contract, and the categorization follows the contract rather than the legs inside it. The full notional shows up in the non-sports column. Trackers Disagree on What Belongs in the Number Artemis reads onchain activity. Polymarket’s CFTC-regulated US venue does not settle that way, so whatever trades there are not inside the $344.2 million. Other platforms draw the line somewhere else again, splitting crypto contracts, combos and exotics by their own rules, which is how the same week produces noticeably different market share depending on where you read it. The direction of travel holds across every tracker. The size of the lead does not.Kalshi’s dependence on that distribution layer also cuts the other way. Robinhood has been building Rothera, an exchange and clearing venture with Susquehanna International Group that would let it list event contracts without a third party in the middle. The channel responsible for roughly a third of Kalshi’s daily flow is working on becoming a venue itself. If you're reading this, you’re already ahead. Stay there with our newsletter.