What the primary record establishes

Kalshi lets users group orders under a limit on contracts matched in a rolling 15-second window. When the limit is hit, the exchange cancels the group’s orders and blocks further orders in the group until reset. Kalshi API, Create Order Group ↗

What the distinction changes

With a limit of 100, fills of 60 contracts at 12:00:10 and 40 at 12:00:22 count together. They are 12 seconds apart despite falling into different fixed 15-second buckets.

What to check before drawing a conclusion

The group control changes order availability. Earlier fills still determine the open position. Track the position and the group’s state separately, and test that the trading system waits for a reset rather than assuming the group reopens when a local timer expires.