Average True Range (ATR) Explained

The Average True Range (ATR) is a volatility metric that measures the average of the true range—the largest of: today’s high minus low, today’s high minus yesterday’s close, or yesterday’s close minus today’s low. Traders use ATR to set stop-loss distances and size positions based on market chop rather than a fixed dollar amount or percentage.

The concept of true range

The true range is the foundation of ATR. On any given day, price might move from open to high to low and back, and the high-low range tells one part of the story. But price can also gap significantly from the prior close.

True range accounts for gaps:

TR = max(H − L, H − Pc, L − Pc)

Where:

• H = today’s high
• L = today’s low
• Pc = yesterday’s close

This three-value comparison captures the full extent of the move, including any overnight or between-session gaps.

Example:

• Yesterday closed at 100.
• Today high is 103, low is 99.
• H − L = 3
• H − Pc = 103 − 100 = 3
• L − Pc = 99 − 100 = −1 (absolute value = 1)
• True Range = max(3, 3, 1) = 3

If there had been a gap:

• Yesterday closed at 100.
• Today opens at 102 (gap up), high is 105, low is 101.
• H − L = 4
• H − Pc = 105 − 100 = 5
• L − Pc = 101 − 100 = 1
• True Range = max(4, 5, 1) = 5

The true range correctly captures the 5-point extent of the move, not just the 4-point intraday range.

Calculating ATR

The Average True Range is simply the moving average of true range values over a lookback period. The standard is 14 periods (14 days on a daily chart, 14 hours on an hourly chart, etc.).

Step 1: Calculate true range for each of the past 14 periods. Step 2: Sum those 14 true range values. Step 3: Divide by 14 to get the average.

On subsequent days, a new true range is calculated, and the average is recalculated using the most recent 14 values (an exponential moving average variant is sometimes used for faster responsiveness).

Example (daily chart):

• Day 1 TR: 2.5
• Day 2 TR: 3.1
• Day 3 TR: 1.8
• … (through day 14)
• Sum of 14 days’ TR: 42
• ATR = 42 / 14 = 3.0

This means the average true range over the past 14 days is 3.0 points. On the next day, a new day’s true range is added, the oldest day is dropped, and ATR is recalculated.

What ATR measures: volatility, not direction

Critical: ATR measures how much price moves, not which direction it moves. A stock that gaps up 5 points has the same contribution to ATR as a stock that gaps down 5 points.

This is why ATR is called a “volatility indicator,” not a “directional indicator.” High ATR means big moves are common (in either direction). Low ATR means price is grinding sideways.

This direction-neutrality is a feature: it lets traders set risk-appropriate stops regardless of whether they are long or short. If ATR is 10 on a $100 stock, a reasonable stop might be 10–15 points away. If ATR is 1 on a $100 stock, a stop might be 1–2 points away.

Using ATR to set stop-loss levels

The most common use of ATR is determining stop-loss distance.

For a long trade:

• Entry: $100
• ATR: $3
• Stop-loss: $100 − 2 × ATR = $100 − $6 = $94

For a short trade:

• Entry: $100
• ATR: $3
• Stop-loss: $100 + 2 × ATR = $100 + $6 = $106

Multipliers of 1, 1.5, 2, or 3 × ATR are common. A 1 × ATR stop is tight and will be hit frequently by chop. A 2–3 × ATR stop gives price more room to breathe before hitting a stop.

The benefit: stops adjust automatically as volatility changes. In a calm market, ATR is low, so stops are tight. In a volatile market, ATR is high, so stops are looser—protecting you from being stopped out by random noise.

Using ATR for position sizing

If you have a fixed dollar risk per trade (say, $500), ATR helps determine position size:

Position Size = Risk $ / (ATR × Price units per contract)

In high-volatility environments (high ATR), this formula naturally reduces position size, because the stop is farther away. In low-volatility environments (low ATR), the formula increases position size, because the stop is closer.

This is a form of volatility-adjusted risk management. Instead of risking the same percentage on every trade, you risk the same absolute dollar amount, adjusted for the volatility of the instrument you’re trading. A volatile penny stock gets a smaller position than a liquid blue-chip stock at the same dollar risk.

ATR as a volatility regime indicator

Rising ATR signals increasing volatility. This is often a warning sign:

• At the end of a trend, volatility often increases as the trend exhausts (more whipsaws, more profit-taking).
• Before an earnings announcement or economic event, ATR often rises (or implied volatility in options rises).
• After a break in support or resistance, ATR often spikes higher.

Falling ATR signals declining volatility—price is grinding in a narrower range. This is often a sign of consolidation before a breakout or a calm, directionless market.

Traders use ATR regimes to adjust their strategies:

• In high-ATR regimes, they tighten stops, take profits faster, and may reduce position size.
• In low-ATR regimes, they may take larger positions and be more patient with winning trades.

Comparing ATR across time frames

ATR on a daily chart is not directly comparable to ATR on a hourly chart. A stock’s daily ATR might be $5, but its hourly ATR might be $1. The scales are different.

To compare, traders normalize ATR as a percentage of price:

ATR % = (ATR / Price) × 100

A stock at $100 with ATR of $5 has ATR % of 5%. A stock at $200 with ATR of $8 has ATR % of 4%. The second stock is less volatile relative to its price.

ATR and average true range in different market conditions

Trending markets: ATR tends to rise during strong trends because larger daily moves occur. Breakout traders like high-ATR markets because big moves are more likely.

Ranging markets: ATR tends to stay low and stable. Range traders like low-ATR markets because chop is predictable and wicks don’t break far outside the range.

At turning points: ATR often increases before a reversal—volatility rises as conviction weakens. A sharp drop in ATR after a rise can signal consolidation before a breakout.

Combining ATR with other indicators

ATR is often combined with other technicals for confirmation:

• ATR expansion + breakout above resistance = higher odds of success.
• Rising ATR + falling moving average crossover = stronger downtrend signal.
• High ATR + doji candle = indecision at high volatility; expect a move soon.

Moving averages and trend lines work well with ATR: if price is above the moving average and ATR is rising, the trend is accelerating. If price is below the moving average and ATR is falling, the trend is weakening.

Limitations of ATR

ATR is not perfect:

• Lagging: ATR reacts to price action after it occurs. A sudden gap can cause ATR to spike one day after a big move.
• Not predictive: High ATR today doesn’t guarantee high ATR tomorrow. A period of calm can follow extreme volatility.
• Context-dependent: An ATR of 5 is high for a $100 stock but low for a $500 stock. Compare ATR % or compare to historical ATR for the same instrument.
• Gap risk: ATR accounts for gaps but cannot predict their direction or magnitude. A stock can gap $20 with an ATR of $3.

See also