A two-leg arbitrage can leave one order resting while you wait for the other to fill. If the platform pauses in between, what happens to the resting order matters. This article summarises Kalshi's documentation on maintenance and pauses. It is not trading advice, and the details can change, so check the current documentation.
The weekly window
Kalshi's documentation says that every Thursday from 3:00 AM to 5:00 AM ET it runs scheduled maintenance, during which a trading pause is in effect. Clients should be prepared for session disconnections during this window and reconnect after 5:00 AM ET.
Trading pause versus exchange pause
In a trading pause you cannot place or amend orders but you can cancel them. In an exchange pause you cannot place, amend or cancel. Exchange pauses are rare; the documentation says they happen when intensive maintenance needs one, or unscheduled when there is a temporary outage. In both cases resting orders remain on the book unless CancelOrderOnPause is set.
CancelOrderOnPause
When placing an order you can set CancelOrderOnPause (REST field cancel_order_on_pause) so that the order is automatically cancelled when a trading or exchange pause begins. The default is that the order stays resting and resumes when activity reopens.
Why it matters for two legs
If you rest a limit order on one platform while waiting to complete the other leg, a pause can freeze that order, and in an exchange pause you cannot cancel it. Decide beforehand whether you prefer the order to stay or to be cancelled, and see the options in order types for two-leg arbitrage. The simplest protection is not to leave an order half-done across a known maintenance window.
Where Arbitrage Agent fits
Arbitrage Agent matches markets across Kalshi and Polymarket, checks the resolution rules on both sides, and shows the result in a live feed with a step-by-step guide for both legs. You place the orders yourself, and the final check of the details is still yours. See the plans or start with the Starter plan.
Related articles
- Order Types for Two-Leg Arbitrage
- Kalshi API Rate Limits
- Kalshi API Guide
- Kalshi Order Book Explained
- Kalshi Order Groups and Rolling Contract Limits
Key terms: Spread · Event Contract