Time in force (TIF) specifies the lifetime and execution conditions of an order. It works alongside the order type: a limit price sets the worst acceptable execution price, while time in force governs whether the order may wait or must execute immediately.
Three common instructions
Good till canceled (GTC) allows an unfilled order, or its remaining quantity, to stay active until filled or canceled, subject to venue rules. Immediate or cancel (IOC) permits immediate partial execution and cancels the remainder. Fill or kill (FOK) requires the entire quantity to execute immediately or cancels the whole order.
For a buy limit order for 12 tokens, suppose only eight are immediately available within its price limit. GTC may buy eight and leave four active; IOC may buy eight and cancel four; FOK buys none under these assumptions.
Choosing the relevant constraint
TIF does not guarantee liquidity, a fill, or a particular fee. Available combinations depend on the venue and product. Check the submitted instruction and subsequent order status: closing an app does not itself cancel an active order.