Stop Loss Placement: Structure Stops, ATR Stops and Sizing From the Stop
Put your stop where the trade idea is wrong, check it against ATR, then size from it. Worked futures and forex examples, tied to prop firm rules.
Put your stop at the price where your trade idea is proven wrong, plus a buffer for normal noise. Then choose a position size so that being stopped out costs a fixed amount. The two common ways to find that price are market structure and volatility, measured with the average true range (ATR). The best stops usually use both, and this guide works through each with real arithmetic.
Key takeaways
- The stop comes first and the position size second. Never pick a size and then fit a stop to it.
- Structure stops go beyond the swing or level that defines the trade; ATR tells you how much buffer to add.
- Stops well inside one ATR sit in normal noise and get hit by random movement.
- A wider stop means a smaller size for the same dollar risk, not a bigger loss.
What should a stop loss do?
A stop has one job: to get you out when the reason for the trade no longer holds. It is not a pain threshold or a round number of dollars. If you buy a bounce off support, the idea is wrong once price holds below that support. If you buy a breakout, it is wrong once price falls back inside the range.
So the question “how many pips should my stop be?” has the order backwards. Find the price that invalidates the idea first. The distance follows from it, and the dollar risk is controlled by size.
Structure based stops
A structure stop sits beyond a feature of the chart that other traders can see too:
- Below the most recent swing low for a long, or above the most recent swing high for a short.
- Beyond the far side of a support or resistance zone.
- Outside an opening range or a consolidation box.
Do not place it exactly at the swing point. Stops cluster there, and price often probes a few ticks past an obvious low before turning. Add a buffer. In forex there is a second detail. Charts usually show the bid, but a short position is closed at the ask, so add the spread to stops on shorts.
ATR based stops
ATR stop for a long = entry − (multiple × ATR)
ATR(14) is the average true range over 14 bars on the timeframe you trade. Many traders use a multiple between about 1 and 3, with lower multiples for shorter holds. A pure ATR stop ignores structure, so it can land just above a swing low that price is likely to test. Using ATR as the buffer beyond structure fixes that.
Worked example: futures
Example figures, Micro S&P 500 (MES), 5 minute chart. You buy at 5,040.00 after a pullback. The pullback’s swing low is 5,028.00, and ATR(14) is 6 points.
- Pure ATR stop at 1.5 × ATR: 5,040.00 minus 9 points = 5,031.00. That sits above the swing low, so a normal retest of 5,028.00 stops you out while the idea is still valid.
- Structure stop with a half ATR buffer: 5,028.00 minus 3 points = 5,025.00. Risk: 15 points.
- Loss per MES contract: 15 × $5 = $75. With $150 of risk per trade, that is 2 contracts.
On the ES contract the same 15 point stop costs 15 × $50 = $750 per contract. The full size contract does not fit a $150 budget at all.
Worked example: forex
Example figures, EURUSD, 4 hour chart, a short trade. Entry is 1.0950, the swing high is 1.0990, the 4 hour ATR(14) is 30 pips, and the spread is 1 pip.
- Structure stop: 1.0990, plus a buffer of a third of the ATR (10 pips), plus the 1 pip spread = 1.1001. Risk: 51 pips.
- ATR check: 51 pips is 1.7 times the ATR, outside normal noise for a 4 hour hold.
- Loss per standard lot: 51 × $10 = $510. With $200 of risk, $200 ÷ $510 = 0.39 lots, a loss of $198.90 at the stop.
Why tight stops often fail
Tight stops look attractive because they allow bigger size and bigger targets in R. In practice they fail for several reasons:
- Noise: if your stop is a fraction of the ATR, ordinary movement can hit it with no change in the picture.
- Slippage: a stop market order fills at the next available price. One tick of slippage on MES is $1.25, which is small on a 15 point stop and large on a 2 point stop.
- Costs: commission is charged per contract, so more contracts at a tighter stop cost more for the same risk.
- Stop runs: obvious stops one tick under a low get taken out by small probes.
Here is the cost point in numbers. Example figures: $150 of risk and $1 of commission per MES contract per side. At a 15 point stop you trade 2 contracts and pay $4 round trip, 2.7% of your risk. At a 3 point stop you trade 10 contracts and pay $20, or 13.3% of your risk, before any slippage.
Never move a stop further away once the trade is open. Moving it closer to protect profit is fine. Widening it turns a planned loss into an unplanned one.
Size from the stop
Contracts or lots = risk per trade ÷ (stop distance × value per point or pip)
Example figures, $200 of risk per trade on MES:
| Stop distance | Loss per contract | Contracts |
|---|---|---|
| 5 points | $25 | 8 |
| 10 points | $50 | 4 |
| 20 points | $100 | 2 |
| 40 points | $200 | 1 |
The dollar risk is $200 in every row. A wider stop is not more dangerous; the position is simply smaller. The real problem comes when even one micro contract or the smallest lot is over budget at your stop. That tells you to skip the trade. More cases are in position sizing for prop firm challenges.
How this fits prop firm rules
- Daily loss limit: keep risk per trade to a small slice of it, often a quarter or less, and size from the stop. See daily loss limits explained.
- Trailing drawdown: with an intraday trailing drawdown, open profit can raise the floor. A trade that runs 3R and then falls back to your original stop can leave less room than you started with. See end of day vs intraday trailing drawdown.
- Position limits: some firms cap the loss on a single position or expect a stop on every trade.
- News: stops can slip badly around high impact releases, and many firms restrict trading near them.
Rules vary by firm; check each firm’s page in our prop firm directory, and filter accounts with find an account.
Questions traders ask
What ATR multiple should I use for my stop?
There is no universal multiple. Many traders use between 1 and 3 times ATR on their trading timeframe. Test the multiple with your own setup, and place it beyond structure where you can.
Should I use a mental stop instead of a real order?
For most traders, no. A resting stop order still works when you freeze, lose your connection or step away, and some prop firm rules expect one.
Is moving my stop to break even a good idea?
Sometimes. Moving it too early turns normal pullbacks into scratch trades, so test a fixed trigger, such as moving the stop once price reaches 1R.
Trading carries a high risk of loss, and stop orders can fill worse than their price in fast markets. Most prop firm accounts are simulated. All figures here are examples, and nothing here is financial advice.