ATR Indicator: How to Use Average True Range for Stops and Sizing

The ATR indicator (Average True Range) measures how much a market typically moves per bar, so traders use it to set stop-losses outside normal noise and to size positions so every trade risks the same amount. ATR tells you how far price moves, not which direction. Among the technical indicators most traders use, ATR is the one built for risk management rather than entry signals.

Quick answer: The Average True Range (ATR) is a volatility indicator created by J. Welles Wilder in 1978 that averages the true range of price bars, usually over 14 periods. ATR is neither bullish nor bearish because ATR measures the size of moves, not their direction. A rising ATR confirms expanding volatility, and traders set stops at 1.5 to 3 times ATR.

---

What is the ATR indicator?

The ATR indicator is a volatility indicator that shows the average size of a market's price bars over a set number of periods, including gaps between bars. J. Welles Wilder introduced the Average True Range in his 1978 book New Concepts in Technical Trading Systems, the same book that introduced the RSI. Wilder built ATR for commodity futures, where overnight gaps meant a simple high minus low range understated how far prices really moved.

ATR is plotted in a panel below price and is expressed in the instrument's own price units: an ATR of 1.50 on a $100 stock means the average bar covers about $1.50; an ATR of 0.0060 on EURUSD means about 60 pips.

How is true range calculated?

True range is the greatest of three values for each bar:

1. The current high minus the current low
2. The absolute value of the current high minus the previous close
3. The absolute value of the previous close minus the current low

The second and third values capture gaps. If a market closes at 100, gaps up to 103 and trades between 103 and 104, high minus low is only 1, but high minus the previous close is 4. True range is 4, which is the move a trader holding overnight actually experienced.

How is the 14-period ATR calculated?

The 14-period ATR starts as a simple average of the first 14 true ranges, then updates with Wilder's smoothing: ATR = ((previous ATR x 13) + current true range) / 14. This behaves like a slow exponential average, so ATR reacts to new volatility gradually rather than jumping on one wide bar. Some platforms use a simple or exponential average instead; values differ slightly, but the reading means the same thing.

What does ATR tell you, and what does it not?

ATR tells you how much a market is moving, and it does not tell you which way. A rising ATR means bars are widening and volatility is expanding; a falling ATR means the market is quieter. Volatility often expands in sharp declines and breakouts, and contracts in tight ranges, but ATR cannot separate a strong rally from a crash. Pair it with moving averages for trend or with support and resistance for structure.

ATR also has no absolute "high" or "low" level. A reading only means something compared with the same market's own history, or after converting it to a percentage of price.

How do you use ATR for a stop-loss?

An ATR stop-loss is placed a fixed multiple of ATR away from entry, commonly 1.5x to 3x ATR. If a market normally moves 1 ATR per bar, a stop closer than that is likely to be hit by ordinary noise even when the idea is still valid.

1. Read the ATR on the timeframe you trade, using the last closed bar.
2. Choose a multiple: about 1.5x for short-term trades, 2x as a common middle ground, up to 3x for swing trades.
3. For a long, place the stop at entry minus the multiple times ATR; for a short, entry plus it.
4. Check that the stop also sits beyond a logical structure level, such as a swing low. If it does not, adjust or skip the trade.

Stops placed exactly at obvious levels are where liquidity sweeps tend to happen. An ATR buffer beyond the level reduces, but does not remove, the chance of being stopped out by a brief spike.

How does an ATR trailing stop work?

An ATR trailing stop follows price at a fixed ATR multiple and only moves in the trade's favour. In an uptrend, each bar recalculates the stop as the close minus a multiple of ATR, and the stop rises when that value is higher than the previous stop but never falls.

The chart shows both parts working together. In the lower panel, the 14-period ATR climbs as the daily ranges widen. On the price panel, the trailing stop sits two ATRs below the close, so as ATR rises the gap between price and the stop widens automatically. A fixed-distance stop would not adapt this way.

What is a chandelier stop?

A chandelier stop is an ATR trailing stop hung from the highest high since entry rather than from the close, typically at 3x ATR for longs (shorts use the lowest low plus 3x ATR). The trade-off with any trailing multiple is the same: 1.5x locks in more but exits on normal pullbacks, while 3x rides longer trends but gives back more at the end. Test the multiple on your market with backtesting.

How do you size a position with ATR?

Position size from an ATR stop is the dollar risk on the trade divided by the stop distance:

Position size = risk per trade / (ATR multiple x ATR)

With $200 of risk, an ATR of $1.00 and a 2x stop, the stop is $2.00 away and the position is 100 units. If ATR doubles to $2.00, the stop moves to $4.00 and the position halves to 50 units. The dollar risk stays at $200 either way.

ATR-based sizing automatically trades smaller when markets are wild and larger when they are calm, while the loss on a stopped-out trade stays constant. The position size calculator does the arithmetic once you know your stop distance.

How do you compare volatility across markets and timeframes?

To compare volatility across markets, convert ATR to a percentage of price: ATR% = ATR / price x 100. An ATR of 2 on a $40 instrument (5%) is far more volatile than an ATR of 5 on a $500 instrument (1%). ATR% puts crypto, forex, index ETFs and commodities on one scale, so you can see why the same dollar risk buys a much smaller position in a more volatile market.

Timeframe matters too. A 14-period ATR on a 5-minute chart measures the typical 5-minute move, and on a daily chart the typical daily move. Read ATR on the timeframe that matches your holding period.

ATR vs Bollinger Bands: what is the difference?

ATR measures the average bar range, while Bollinger Bands measure how widely closes are spread around a moving average. ATR is a single number in price units, ideal for stop distances and sizing. Bollinger Bands use the standard deviation of closes to draw an envelope, which is better for spotting a squeeze (often inside triangle patterns) and judging whether price is stretched. Bollinger Bands ignore gaps and intrabar extremes; ATR includes them. Many traders use Bollinger Bands to spot the breakout and ATR to place the stop and size it.

Can ATR be used for targets and trade filters?

Yes. ATR can set realistic profit targets and filter out conditions that do not suit a strategy.

• Targets: 2x to 4x ATR keeps expectations in line with how far the market actually moves.
• Reward-to-risk: a 2x ATR stop with a 4x ATR target is 2:1. The chart below shows the win rate needed to break even at each ratio; see risk-reward ratio explained.

• Filters: some strategies only take breakouts when ATR is rising, or skip mean-reversion trades when ATR is unusually high versus its own average.

What are the limits of the ATR indicator?

1. No direction. ATR needs a trend or structure tool to decide long or short.
2. Lag. Wilder's smoothing understates volatility for a few bars after a shock and overstates it after the market calms.
3. Relative values. Readings cannot be compared across instruments without ATR%.
4. Events. ATR describes typical movement, not worst case. A news release or weekend gap can move price several ATRs past any stop.

Can AI improve ATR signals?

AI tools can help with ATR-based rules, for example by scanning many markets for unusual ATR expansions or testing which stop multiple suited a market historically. AI trading signals and screeners can flag candidates far faster than a person scrolling charts.

The limits stay the same. The choice of multiple, timeframe and structure level is subjective, scanners produce false positives, and a rule that fitted the past can fail in a new volatility regime. Any AI-assisted ATR rule still needs backtesting and human judgement.

How do you use ATR in a prop trading challenge?

ATR is arguably the most useful indicator inside a prop challenge, because the challenge is mainly a test of risk control. ATR keeps stops outside normal noise and, through sizing, keeps each loss small relative to the account's hard limits.

At Velotrade, a multi-asset prop trading firm offering simulated evaluations, those limits are a daily loss limit, which resets every day at 00:30 UTC and is set from the higher of your balance or equity at that moment, and a static maximum drawdown, a fixed dollar floor set at activation that never moves.

Worked example with round numbers

Take a $100,000 CLASSIC 1-Step evaluation: the daily loss limit is 4% ($4,000 from a $100,000 balance) and the static floor is $93,000, leaving $7,000 of room.

1. Risk per trade: 0.5% of the account, or $500.
2. Read ATR: the instrument trades at $100 and the 14-period hourly ATR is $1.00.
3. Set the stop: 2x ATR, $2.00 from entry, beyond the nearest swing low.
4. Size the trade: $500 / $2.00 = 250 units.
5. Check the limits: one full loss is one eighth of the daily limit and one fourteenth of the drawdown room. A personal rule of stopping after three losses in a day ($1,500) keeps the daily limit far away.

If volatility doubles and ATR rises to $2.00, the stop becomes $4.00 and the position drops to 125 units, so the loss is still $500. Keeping 250 units with the wider stop would risk $1,000 a trade, and four losses would hit the daily limit. The opposite mistake, forcing a $0.50 stop to trade 1,000 units, puts the stop inside half an ATR of noise. News trading is allowed at Velotrade, so also size for a release moving price several ATRs past the stop. Compare plans on the challenges page.

Vittorio De Angelis has said that charts "condense information about participants' behavior", and ATR is a clean example: one line summarising how hard buyers and sellers are pushing price around. Fundamentals and flows still drive direction; ATR tells you how much room to give the idea.