Average True Range Percent (ATRP): The Volatility Indicator That Lets You Compare Any Stock
Quick question: which stock is more volatile — one that swings $5 a day while trading at $400, or one that swings $2 a day while trading at $20?
If you only look at the raw Average True Range (ATR), the $400 stock looks "more volatile" simply because $5 is a bigger number than $2. But relative to price, the $20 stock is actually moving twice as much. This is exactly the blind spot that Average True Range Percent (ATRP) was designed to fix.
What Is Average True Range Percent (ATRP)?
ATRP takes the classic Average True Range indicator and expresses it as a percentage of a bar's closing price instead of a raw dollar (or point) figure. Where ATR measures volatility in absolute terms, ATRP normalizes it — turning volatility into a percentage that means the same thing no matter what the underlying stock costs per share.
That one small tweak solves a big practical problem: ATR values can't be fairly compared across different stocks, but ATRP values can.
The ATRP Formula
The calculation is refreshingly simple:
ATRP = (Average True Range ÷ Close) × 100
Where:
- Average True Range (ATR) is the average of the "true range" (the greatest of: current high minus current low, current high minus previous close, or current low minus previous high) over a chosen lookback period — 14 periods is the most common default.
- Close is the closing price of the current bar.
- Multiplying by 100 converts the ratio into a percentage.
So if a stock has an ATR of $2.50 and is trading at a $50 close, its ATRP is:
(2.50 ÷ 50) × 100 = 5%
That 5% figure tells you, on average, how much this stock moves per bar relative to its price — a number you can now stack up against any other stock, regardless of share price.
Why ATRP Beats Plain ATR for Comparisons
ATR is measured at an absolute level. That means higher-priced stocks will almost always show higher ATR values than lower-priced stocks, even if the lower-priced stock is actually choppier on a percentage basis. This makes ATR great for position sizing and stop-placement on a single stock, but misleading when you try to rank or compare volatility across a watchlist.
ATRP fixes that by putting every stock on the same percentage scale.
| Scenario | Price | ATR | ATRP |
|---|---|---|---|
| Stock A | $400 | $5.00 | 1.25% |
| Stock B | $20 | $2.00 | 10.0% |
Looking only at ATR, Stock A appears more volatile. Looking at ATRP, it's clear Stock B is actually moving far more relative to its price — information that matters a lot if you're comparing risk across a portfolio or scanning for the "most volatile" names in a sector.
How Traders Use ATRP
1. Comparing Volatility Across a Watchlist
Because ATRP is expressed as a percentage, it's the go-to tool when you want to rank multiple stocks — regardless of share price — by how much they typically move.
2. Screening for Volatility
Day traders and swing traders often screen for a minimum ATRP threshold to filter out stocks that are too "quiet" to offer meaningful intraday range, or conversely, to filter out names that are too wild for their risk tolerance.
3. Position Sizing
Since ATRP reflects volatility as a percentage of price, it can help standardize how much capital or how many shares to allocate to different positions so that each trade carries a comparable amount of dollar risk.
4. Setting Stops and Targets
Just like ATR, ATRP can inform stop-loss placement — the difference is that using the percentage figure makes it easier to apply a consistent volatility-based stop methodology across stocks trading at very different price levels.
5. Spotting Volatility Contraction or Expansion
Watching ATRP over time on a single stock can reveal periods of unusually low volatility (often precursors to a breakout) or spikes in volatility (which can signal news events, earnings reactions, or trend exhaustion).
ATRP vs. ATR: Quick Comparison
| Feature | ATR | ATRP |
|---|---|---|
| Units | Dollars / points | Percentage |
| Best for | Single-stock stop placement | Cross-stock volatility comparison |
| Affected by share price | Yes — higher-priced stocks skew higher | No — normalized |
| Common use case | Setting a dollar-based stop | Screening or ranking volatility |
| Calculation complexity | Base calculation | ATR ÷ Close × 100 |
A Simple Way to Start Using ATRP
- Pick your lookback period. 14 periods is standard, but shorter periods (7–10) react faster to recent volatility, while longer periods (20+) smooth things out.
- Add ATRP to your watchlist columns. Most modern charting platforms let you display ATRP as a sortable column, making it easy to rank an entire watchlist by relative volatility.
- Use it as a filter, not a signal. ATRP tells you how much a stock tends to move — it doesn't tell you which direction. Pair it with trend or momentum indicators to build a complete picture.
- Track changes over time. A sudden jump in ATRP can flag that something has changed in a stock's character — worth investigating before you trade it the same way you always have.
Frequently Asked Questions
What does ATRP stand for? Average True Range Percent — it expresses the Average True Range indicator as a percentage of a bar's closing price.
How is ATRP different from ATR? ATR measures volatility as a raw dollar/point figure, while ATRP converts that same volatility into a percentage of price, making it possible to fairly compare volatility across stocks trading at different price levels.
What's a "good" ATRP value? There's no universal answer — it depends on your trading style and the asset class. Day traders often look for higher ATRP for more intraday range, while conservative investors may prefer lower ATRP for steadier price action. What matters most is comparing ATRP consistently across the stocks you're evaluating.
Can ATRP be used on any timeframe? Yes. ATRP can be calculated on intraday, daily, weekly, or monthly bars — the interpretation stays the same, just scaled to whatever period you're analyzing.
Does ATRP predict market direction? No. ATRP is purely a volatility measure — it shows how much a security tends to move, not which way it's likely to move. It's best used alongside trend and momentum tools.
Final Thoughts
Average True Range Percent takes a well-established volatility tool and makes it genuinely useful for apples-to-apples comparisons. If you've ever tried to compare how "choppy" two different stocks are and found ATR values that just didn't seem to add up, ATRP is the fix — a clean, percentage-based way to measure and compare volatility across any security, at any price point.
This article is for educational purposes only and does not constitute financial or investment advice. Always do your own research and consider your risk tolerance before trading.
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