Kalshi-specific Rules and Nuances

Contracts are whole numbers

Kalshi has no fractional contract. Order sizes are rounded down to a whole number of contracts, so a dollar amount that works out to 12.7 contracts places 12.

The practical effect is on very small orders: if your dollar size divided by the outcome price lands below one contract, nothing is placed. There is no dollar minimum on Kalshi (unlike HIP-4's 10 USDH floor). The effective minimum is simply 1 contract, which at a 6¢ outcome price is about $0.06 and at a 94¢ price is about $0.94.

Tick size varies by market, and can be finer than a cent

Most Kalshi markets quote in whole cents. Some markets ("deci-cent" series) quote in tenths of a cent in the tails (below 10¢ and above 90¢) while still stepping a full cent in the middle of the range.

The limit price stepper on the order form uses the tick the selected market actually reports, so the +/- buttons move by the right increment automatically. If you type a price finer than the market allows, Kalshi snaps it onto the nearest valid price.

Only active markets accept orders

A Kalshi market accepts orders only while its status is active. Markets that have been created but not yet opened, or that have closed and moved into settlement, will not accept orders.

The Kalshi tab is a snapshot, not a full catalogue

Kalshi lists tens of thousands of open markets. The Kalshi tab loads a curated snapshot of the most relevant events rather than the whole catalogue, so:

• There are no category tabs or pagination. It is one flat, scrollable grid.

There is no Split or Merge

Split and Merge are on-chain conditional-token operations specific to Polymarket. Kalshi issues both sides of a market natively, so those buttons do not appear on Kalshi events and the operation is rejected if attempted.

Fees. Unlike Polymarket and HIP-4, Kalshi charges trading fees on event contracts, and the fee depends on the contract price. Fees are deducted by Kalshi at fill time and show against your fills. Check Kalshi's published fee schedule for the current rates before sizing tight-spread strategies.