Time in Force

Time in force is the instruction attached to an order that says how long it may stay active. Good-til-cancelled leaves it resting on the book until it fills or you remove it. Immediate-or-cancel fills whatever it can at once and cancels the remainder. Fill-or-kill requires the entire order to execute immediately or none of it does. Day orders expire at the end of a trading session, where the venue defines one — crypto markets run continuously, so not every venue offers it. Choosing the wrong instruction is a common source of surprise: an order you assumed had expired can still be resting on the book days later.