ARMFThe stop-loss did not trigger: when protection does not help
The complaint «the stop-loss did not trigger» almost always means one of four things: the order filled worse than expected or did not fill at all. A stop limits the loss in a normal market and gives no full guarantee in a fast one. There are four situations in which the actual loss turns out larger than the calculated one or the position stays open altogether. Each has clear mechanics — and different ways to reduce the consequences.
Four causes: a gap, slippage in trading, the spread and a stop-limit
A price break through the stop level
The market opens far from the closing price — after the weekend or a major event. The stop order triggers at the first available price, and it can be noticeably worse than the one stated.
A gap is the only case where an ordinary stop-market does not do its job in terms of the size of the loss, although it does close the position.
A fill at a worse price
At the moment of a sharp move price passes the stop level in fractions of a second, and a market order is filled at the next available quote.
Slippage can also work in your favour — when a take-profit fills in a fast move — but on average it works against the position.
The stop taken out by a widening spread
In illiquid hours and at moments of news the spread widens. A stop on a buy is filled at the bid, and it can be touched even without a move in the mid price.
It is especially noticeable on tight stops: a spread widening from 1 to 5 pips on a stop 15 pips long is a third of the distance.
The order stayed unfilled
If a stop-limit is placed instead of a stop-market, on a fast pass of price the limit order finds no counterparty. The position stays open while the loss keeps growing.
The only one of the four cases fully in the trader's hands: it is a question of the order type, not of market behaviour.
What to do about slippage on the currency market
These scenarios cannot be removed entirely — their contribution to the result can be reduced. Below are practical measures and what each of them actually gives.
| Measure | What it reduces | What it does not give |
|---|---|---|
| A stop-market instead of a stop-limit | The risk of being left with an open position | Does not protect from slippage |
| Closing positions before the weekend | The risk of a gap at the opening of the week | Does not help with events inside the week |
| A smaller size for carried positions | The size of the loss on a gap | Does not change the probability of the gap itself |
| Not entering minutes before macro data | Slippage and spread widening | Does not cancel the reaction to unexpected news |
| A guaranteed stop where the broker offers one | The exit price is fixed in advance and a break does not move it | Paid for by a separate fee or a wider quote |
A negative balance. On an extreme move the loss can exceed the deposit: positions are closed at the available prices rather than at the stop-out level. Negative balance protection is not offered by every broker and does not apply in every jurisdiction — the clause is looked for in the agreement before the money is deposited. The textbook case is 15 January 2015: the Swiss National Bank removed the franc's cap against the euro, and part of the retail accounts ended up with a negative balance.
How much to allow for slippage
The difference between the calculated and the actual loss is worth building into the plan in advance — as a correction to the risk rather than as an unpleasant surprise. The order of magnitude depends on the trading conditions.
| Situation | Typical discrepancy | What to do about it |
|---|---|---|
| A major pair, active hours, a normal market | 0-1 pip | No separate correction is needed |
| A major pair, the Asian session | 1-3 pips | Do not place a stop shorter than 20-25 pips |
| A macro data release | From a few to tens of pips | Do not hold a position at the moment of release |
| The opening of the week after a weekend event | A gap of any size | Reduce the size of carried positions |
The practical rule is simple: if your usual stop is comparable with typical slippage, risk management stops working not because the calculation is wrong but because reality does not fit into it. In that case what changes is not the calculation but the trading style — a longer stop and a reduced lot at the same risk amount.
Frequently asked questions
Can a broker fail to execute my stop-loss?
A stop-market is executed, but at the available price — the discrepancy is explained by slippage rather than by a refusal. The situation where the position stays open is typical of a stop-limit: by its nature it does not guarantee a fill. If the discrepancies are systematic and unrelated to market events, that is a reason to compare the fills with an independent quote source.
How do you trade the news without catching slippage?
The most reliable way is not to have open positions at the moment of release. If the position is already open, a reduced size helps, along with an understanding that the actual loss can turn out one and a half to two times larger than calculated.
What is a guaranteed stop-loss and is it worth the money?
It is an order the broker undertakes to execute strictly at the stated price even on a gap — for a separate fee or a widened spread. The economic sense appears when carrying positions through weekends and events: you are buying certainty about the loss. Availability and terms depend on the broker and the jurisdiction.
How large can slippage be on major pairs?
In a normal market fractions of a pip, in the Asian session single pips, at the moment of a key data release tens of pips. That is exactly why a tight stop and trading the news go badly together: the discrepancy is comparable with the risk itself.
Why did the stop trigger when price on the chart did not reach it?
The chart is usually drawn from the bid, and a stop on a buy is executed at the bid — but a stop on a sell is closed at the ask, that is a spread's width above the visible line. When the spread widens the difference grows, and the level is touched without a move in the mid price.
What happens to a stop on a gap at the opening of the week?
The order is activated at the first available price after the open. If the break passed through the level, the position will close worse than the calculated price, and the actual loss will exceed the planned one by the size of the gap.
How do you reduce gap risk if a position has to be carried?
Reduce the size for carried trades and understand that the calculated risk is not guaranteed over the weekend. Some traders close half the position before the weekend — that is a compromise between protection and keeping the idea.
Does slippage ever work in the trader's favour?
Yes, when a take-profit fills in a fast move price can go beyond the level. But the distribution is asymmetric: in stressful moves it is more often the side the market is running against that suffers.
Does a limit entry save you from slippage?
A limit order on entry guarantees the opening price but does not solve the exit: closing at the stop still goes as a market order. Slippage moves from the entry to the exit rather than disappearing.
How do you check that the discrepancies are not the broker's fault?
Compare the time and price of the fill with quotes from an independent source — for example data from another provider for the same second. Isolated discrepancies in a fast market are normal; systematic ones always in the same direction are a reason for questions.
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