ProcessIntermediate
Kill or Fill
syn. Fill or Kill / FOK
An order instruction that requires immediate and complete execution; if the full order cannot be filled instantly, the entire order is canceled.
Last updated: February 10, 2026
1
The trader submits a Kill or Fill (Fill or Kill) order specifying the full desired volume.
2
The execution system checks if the full volume is immediately available at the requested price.
3
If yes, the entire order is filled instantly.
4
If no, the entire order is immediately canceled — no partial fill occurs.
5
This is used when partial execution would be worse than no execution.