A stop-loss is a market order waiting for a trigger
Posted: Sat Oct 31, 2026 7:28 pm
A lot of confusion comes from treating the stop price like a guarantee. It's a trigger. Once the market touches it, a market order goes out and fills at whatever is available, which can be the stop price, a bit worse, or much worse.
That's why stops placed just under an obvious swing low can fill several pips lower during a fast move. The stop did exactly what stops do.
Some traders switch to stop-limit orders to prevent that, which brings the opposite problem. If price blows through the limit, the order never fills and the position sits there with no protection at all. For a scalper, an unfilled exit is arguably worse than a slipped one.
A practical approach is to size positions assuming the stop will slip by a typical amount, then check actual stop fills against intended levels each month. The difference is the real cost of using stops.
What is the average slippage on stop fills in your own history?
That's why stops placed just under an obvious swing low can fill several pips lower during a fast move. The stop did exactly what stops do.
Some traders switch to stop-limit orders to prevent that, which brings the opposite problem. If price blows through the limit, the order never fills and the position sits there with no protection at all. For a scalper, an unfilled exit is arguably worse than a slipped one.
A practical approach is to size positions assuming the stop will slip by a typical amount, then check actual stop fills against intended levels each month. The difference is the real cost of using stops.
What is the average slippage on stop fills in your own history?