Trigger order

An order that stays inactive until a specified price is reached, then converts into a market or limit order. Take-profit and stop-loss orders are both trigger orders.

Definition

A trigger order is an instruction held in reserve. It does not sit on the order book and cannot be filled while it waits. Only when the price reaches the trigger level does it become a live order, either a market order or a limit order, depending on how you configured it.

Why it is a category, not a single order type

Take-profit, stop-loss, stop market and stop limit are the same mechanic with different intentions and different second halves. Understanding the mechanic once means understanding all of them: choose the price that wakes the order up, then choose what kind of order it wakes up as.

Which price fires it

Exchanges usually trigger on the mark price rather than the last traded price, because the mark price is built to resist brief spikes and manipulation. That choice decides whether a momentary wick in an illiquid market closes your position or leaves it untouched. It is a per-exchange setting, sometimes even per order, and worth confirming rather than assuming.

What can still go wrong

A trigger order is not a guarantee that your loss stops at the trigger price. A market variant fills at whatever the book offers, a limit variant may not fill at all, and neither is enforced by anything until it is actually submitted.

Flagging the order reduce-only prevents the most common accident, where a trigger fires on a position that is already closed and opens a new one in the opposite direction.

Where you will run into it

Every perpetual DEX exposes trigger orders, usually through a take-profit and stop-loss panel on an open position rather than a separate order ticket. On protocols with a two-step execution model, a keeper is what submits the transaction once the condition is met.