Stop
Also called: stop-loss, stop order
A level resting below your position that turns into a market order when the price reaches it.
In practice
You name a level. If the market falls to it the stop fires and sells at whatever the next published price is — which can be below the level you named. That is what makes it a trigger rather than a price promise, and it is true of real stops too.
What it is not
Not a floor under your losses. A fast fall can carry the price past your level before anything fills. Aureus records the gap between your level and the actual fill on the order, rather than pretending the fill landed on your number.