Average True Range Indicator: How to Use ATR for Stop-Loss and Position Size

A dull mid-morning wobble takes out your stop, and two days later the stock is right where you expected. The idea was fine. The stop ignored how much that stock usually moves. The average true range indicator (ATR) measures that typical daily range.

Below: how ATR is calculated, what it can and can’t tell you, and how to use it for stops and position size.

In this article

1. What is the average true range indicator?
2. Step 1: Get comfortable with the true range
3. Step 2: Average those true ranges
4. Step 3: Adjust the period if it suits you
5. What ATR tells you, and what it won’t
6. Use 1: Setting stop-losses with ATR
7. Use 2: The chandelier exit, a trailing stop
8. Use 3: Sizing positions with ATR
9. Use 4: Catching shifts in volatility
10. How ATR stacks up against other volatility tools
11. Where ATR falls short
12. Trying ATR on Indian stocks
13. Frequently asked questions
14. Key takeaways

What is the average true range indicator?

Investopedia describes ATR as a technical analysis indicator introduced by market technician J. Welles Wilder Jr. in his book “New Concepts in Technical Trading Systems”. It measures market volatility. It was first built for commodities markets and later applied to all types of securities.

Investopedia adds that ATR is usually taken as a 14-day moving average of a series of true range values. Strip away the jargon and ATR answers one plain question: how much does this stock usually move in a day?

ATR doesn’t tell you where a stock is going. It tells you how much room it needs to get there.

Step 1: Get comfortable with the true range

High minus low misses overnight gaps. True range plugs that hole. Going by Investopedia’s explanation, true range is the greatest of these three:

1. Today’s high minus today’s low
2. The absolute value of today’s high minus yesterday’s close
3. The absolute value of today’s low minus yesterday’s close

TR = Max[(H − L), |H − Cp|, |L − Cp|]

Why bother with the extra two terms

Take a stock that closed at Rs 500 yesterday, gapped up to open at Rs 520, and then traded between Rs 515 and Rs 525 today. The numbers are illustrative.

• High − low = 525 − 515 = Rs 10
• |High − previous close| = |525 − 500| = Rs 25
• |Low − previous close| = |515 − 500| = Rs 15

So the true range is Rs 25. The simple range of Rs 10 badly understates how far the stock travelled since the last close.

Step 2: Average those true ranges

For the very first ATR reading, Investopedia says you take a simple average of the true ranges across the period, which is usually 14 days.

From the next day on, ATR is smoothed with this formula:

ATR = [(Previous ATR × (n − 1)) + Current TR] ÷ n

With n = 14, each fresh day’s true range carries a weight of 1/14 and the earlier ATR carries the rest. It moves without lurching.

Worked example

Suppose the previous 14-day ATR is Rs 18 and today’s true range comes in at Rs 32 (illustrative):

ATR = [(18 × 13) + 32] ÷ 14 = (234 + 32) ÷ 14 = 266 ÷ 14 = Rs 19.0

One wild day pushes ATR up a little. It doesn’t make it jump. That’s deliberate.

Step 3: Adjust the period if it suits you

Investopedia points out that traders can pick periods shorter than 14 days to get more signals, while longer periods tend to give fewer.

• Shorter (for example 7): picks up recent volatility faster. Fits short-term trading.
• Standard (14): what most platforms load by default.
• Longer (for example 20 or 50): a smoother line. Fits positional trading.

What ATR tells you, and what it won’t

On this, Investopedia doesn’t leave room for doubt: the indicator does not indicate price direction. Its main use is measuring volatility, including the volatility that comes from gaps and limit up or down moves.

• Rising ATR: the stock is swinging more than it used to. You often see this in sell-offs, breakouts and around news.
• Falling ATR: the stock has quietened down, which is common during consolidation.
• High ATR doesn’t mean bullish, and low ATR doesn’t mean bearish.

Compare ATR as a percentage

An ATR of Rs 20 on a Rs 200 stock is nothing like Rs 20 on a Rs 2,000 stock. Convert it to a percentage:

ATR% = ATR ÷ Price × 100

• Rs 20 ATR on a Rs 200 stock = 10% (very volatile)
• Rs 20 ATR on a Rs 2,000 stock = 1% (calm)

Use 1: Setting stop-losses with ATR

This is where most traders start. Rather than a fixed percentage stop, you put the stop a chosen multiple of ATR away from your entry.

Stop = Entry − (Multiple × ATR) for a long trade.

Example

Entry at Rs 1,000, ATR of Rs 25, and a multiple of 2 (illustrative):

Stop = 1,000 − (2 × 25) = Rs 950

Now the stop sits beyond the stock’s ordinary daily noise. If price does fall that far, it’s a fair sign something has actually changed.

Picking the multiple

• 1-1.5× ATR: tight. Works for intraday or very short trades, but expect to get stopped out often.
• 2× ATR: a common middle path for swing trades.
• 3× ATR or more: wide. Better for trend-following and positional trades.

A stop inside a stock’s normal daily range isn’t a stop. It’s a donation to the market.

Use 2: The chandelier exit, a trailing stop

Investopedia also covers the “chandelier exit”, which Chuck LeBeau developed. It hangs a trailing stop below the highest high the stock has touched since you got in, and the gap is a multiple of ATR.

Chandelier stop = Highest high since entry − (Multiple × ATR)

Each new high drags the stop up with it. The stop never comes back down. You stay with the trend and bank gains as you go.

Example

You bought at Rs 1,000. The stock has since climbed to Rs 1,150 and ATR is now Rs 28. Using a 3× multiple (illustrative):

Stop = 1,150 − (3 × 28) = 1,150 − 84 = Rs 1,066

The stop is now above your buy price. Barring a gap straight through the stop, this trade can no longer turn into a loss.

Use 3: Sizing positions with ATR

According to Investopedia, ATR can also help decide how big a trade should be, taking into account both the trader’s risk tolerance and how volatile the underlying is.

Pair an ATR stop with fixed fractional sizing and the arithmetic is simple:

1. Rupee risk = Capital × Risk % (for example Rs 5,00,000 × 1% = Rs 5,000)
2. Risk per share = Multiple × ATR (for example 2 × Rs 25 = Rs 50)
3. Quantity = 5,000 ÷ 50 = 100 shares

Run the same numbers on a jumpier stock with ATR of Rs 50 and you get a Rs 100 stop and just 50 shares. Volatility evens out across positions on its own. Our guide on fixed fractional position sizing goes through the method properly.

Use 4: Catching shifts in volatility

• ATR shrinking to multi-month lows often shows up before a breakout, somewhat like a Bollinger squeeze.
• ATR spiking while a stock falls can point to panic. Some traders hold off buying until ATR settles.
• Ahead of results, look at ATR to get a sense of a normal move, then measure the actual post-results move against it.

How ATR stacks up against other volatility tools

Tool	What it measures	Best for
ATR	Average size of daily moves, including gaps	Stops and position sizing
Bollinger Bands	Price relative to a moving average, scaled by standard deviation	Relative high/low and squeezes
India VIX	Expected Nifty volatility implied by options	Market-wide risk mood
Historical volatility	Standard deviation of returns	Options and risk models

For day-to-day trade management, we find ATR the most practical of the lot, because it’s in rupees and drops straight into a stop-loss or position-size calculation.

Where ATR falls short

• No direction: it won’t tell you whether to buy or sell.
• Lagging: it’s built from past ranges, so a sudden volatility shock only shows up bit by bit.
• Price-level bias: raw ATR goes up as price goes up. Use ATR% when comparing stocks.
• Gaps still hurt: an ATR stop can’t save you from a large overnight gap right through your stop level.
• Subjective multiples: the right multiple depends on your timeframe and style. Test it before you trust it.

Trying ATR on Indian stocks

Nearly every Indian broker’s charting tool has ATR in its indicator list. Try this once:

1. Add ATR (14) to the daily charts of two Nifty 50 stocks from different sectors.
2. Convert each reading to ATR% using the current price.
3. See how far apart their “normal” daily movement really is.
4. Go back to a recent trade where your stop got hit. Was the stop inside 1× ATR?

If you want a wider grounding, Zerodha Varsity’s technical analysis module covers indicators in detail.

Frequently asked questions

Does ATR work for intraday trading?

Yes. Put ATR on intraday timeframes like 5-minute or 15-minute charts to size stops for day trades. Daily ATR is also handy for estimating how far a stock might travel in a single session.

Can ATR be used for options?

ATR measures the underlying’s realised range. Options traders often set it against implied volatility to judge whether premiums look cheap or expensive.

What counts as a “good” ATR value?

There isn’t a good or bad ATR. It just describes volatility. What matters is that your stop and position size match it.

Key takeaways

• ATR measures volatility through the true range, which counts gaps.
• The standard setting is 14 periods. Shorter reacts faster, longer is smoother.
• ATR says nothing about direction.
• Use 1.5-3× ATR for stops, depending on your timeframe.
• The chandelier exit trails a stop under the highest high by a multiple of ATR.
• Pair ATR stops with fixed fractional sizing to keep risk consistent from trade to trade.

For more tools, read our guide to technical analysis for Indian stocks and our explainer on Bollinger Bands.

This article is for educational purposes only and is not investment advice.