Forex glossary

Fill Or Kill Order (FOK) in Forex

A clear definition of Fill Or Kill Order (FOK), with practical context for reading markets and making better trading decisions.

Level 2 · From Prices to PracticeOrders & execution

Definition

A Fill or Kill (FOK) order requires the full requested quantity to be executed immediately; otherwise the entire order is cancelled. It combines an all-or-none quantity condition with immediate execution.

How It Works

Orders are instructions, and their exact behavior depends on the conditions attached to them: price, quantity, timing, and what should happen if execution is only partly available. Before confirming an order, read the order type and validity fields rather than assuming every instruction behaves like a market order.

Why It Matters

This matters because two orders aimed at the same market can produce very different outcomes. Level 2 treats order mechanics as a safety skill: configure the instruction you actually intend, then review it before submission.

Key Takeaway

A Fill or Kill (FOK) order requires the full requested quantity to be executed immediately; otherwise the entire order is cancelled.

Practical forex example

A trader submits an FOK order for 5,000 units at a specified limit. If only 4,000 units can be filled immediately, no partial fill is accepted and the order is cancelled.

Why Fill Or Kill Order (FOK) matters

Understanding Fill Or Kill Order (FOK) helps traders interpret market information, plan decisions, and manage risk with more context.

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