In terms of market making, the market creation of Kalshi is roughly similar, except that the collateral party does not use USDC and does not operate on-chain. To create a market on Kalshi, it must be initiated directly by the team, approved by the exchange, or finally reviewed by user suggestions. Polymarket events can produce mutually exclusive outcomes, which will be bundled together for collateral, with 1 USD covering the entire collection.

On Kalshi, each outcome is an independent binary (yes or no) contract, and the market is created by bundling all these binary contracts together and presenting them in the form of a single market on the user interface. This does not affect end users, as the display of the 2028 US presidential election markets on Polymarket and Kalshi is the same, but fundamentally, there are significant differences between them, with several key distinctions. The multi-outcome markets on Kalshi functionally resemble those on Polymarket, only in a different context.

Since each market on Polymarket is fully collateralized by USDC, the sum of probabilities must always be 100%. Kalshi differs in this respect because when these binary contracts are combined, the probabilities may not add up to 100%, resulting in arbitrage opportunities. This is not to say that Kalshi's markets are not fully collateralized - they are indeed collateralized - but their composition is different from Polymarket, and these structural differences lead to Polymarket and Kalshi each using different strategies.