Orders & execution
What does a Fill-or-Kill (FOK) routing instruction require from the market maker?
By Easy Money Scanner · Educational reference · Not investment advice
The short answer
A Fill-or-Kill (FOK) order requires the entire order to execute immediately in full, or it is canceled entirely, giving the market maker no option for partial fills.
How it works
FOK is stricter than IOC because it demands complete execution at once. It's typically used for larger block trades where partial fills would be undesirable or operationally inconvenient.
An example
An institutional trader submits a FOK order for 50,000 shares; if the market can't fill the full amount instantly, the entire order is canceled.
Risk & limitations
FOK orders frequently fail to execute in less liquid stocks, so traders may need to use smaller order sizes or alternative order types to get filled.
Examples are hypothetical, not trade recommendations. US contract and regulatory references do not automatically apply in Canada. Rules, margin requirements and broker policies can change; confirm them with the relevant authority and your broker.