Direct Answer
The Choppiness Index is an indicator developed by E.W. Dreiss that gauges how much a market is trending versus chopping sideways. Unlike most technical indicators, it makes no claim about direction, a high or low reading says nothing about whether price is likely to go up or down, only about how much net progress price is making relative to how much it's been moving around to get there.
Key Takeaways
- The Choppiness Index measures whether a market is trending or choppy, not which direction it's moving.
- It's calculated from the sum of Average True Range over a lookback period divided by the total high-low range covered over that same period, scaled logarithmically to a 0-100 reading.
- Readings near 100 suggest a sideways, range-bound market; readings near 0 suggest a strongly trending one. Because it carries no directional information, it's typically paired with a trend or momentum indicator.
What Is the Choppiness Index?
The Choppiness Index is an indicator developed by E.W. Dreiss that gauges how much a market is trending versus chopping sideways. Unlike most technical indicators, it makes no claim about direction, a high or low reading says nothing about whether price is likely to go up or down, only about how much net progress price is making relative to how much it's been moving around to get there. A market that grinds steadily in one direction produces a low reading; a market that whipsaws back and forth without covering much net ground produces a high reading.
The Formula
Choppiness Index = 100 × log10( SUM(ATR, n) / (MaxHigh(n) − MinLow(n)) ) / log10(n)
Where SUM(ATR, n) is the sum of the Average True Range over the last n periods (commonly 14), and MaxHigh(n) / MinLow(n) are the highest high and lowest low reached over that same n-period window. The numerator compares the total bar-to-bar movement (ATR summed across every bar) against the net high-low range the market actually covered; the log10(n) denominator scales the result onto a 0-100 axis regardless of the period length chosen.
The intuition: in a clean trend, price rarely retraces, so the sum of each bar's true range stays close to the total distance covered from the period's low to its high, the ratio inside the log stays near 1, and the Choppiness Index stays low. In a choppy, sideways market, price moves back and forth repeatedly without covering much net distance, so the sum of ATR is far larger than the net range, pushing the ratio, and the Choppiness Index, higher.
Worked Example
Hypothetical example, for education only.
Using the commonly cited 14-period lookback (n = 14):
SUM(ATR, 14) = $24.50
MaxHigh(14) = $118.75, MinLow(14) = $104.25, so the 14-period range = 118.75 − 104.25 = $14.50
Ratio = 24.50 / 14.50 = 1.690
log10(1.690) = 0.228; log10(14) = 1.146
Choppiness Index = 100 × 0.228 / 1.146 = ≈ 19.9
A reading of roughly 19.9 sits well toward the low end of the 0-100 scale, consistent with a market where the sum of true range over the period stayed close to the net distance covered, a description of a comparatively trending, low-chop stretch rather than a sideways one.
How the Choppiness Index Is Used
Reading the scale
Values near 100 are commonly read as choppy, range-bound conditions where breakout and trend-following approaches tend to struggle. Values near 0 are commonly read as strongly trending conditions. Some traders and platforms reference the Fibonacci-derived levels of 61.8 and 38.2 as informal high/low thresholds. This is a commonly cited heuristic, not a fixed rule, and default thresholds can vary by charting platform, so it's worth verifying against your own.
Filtering, not signaling
Because the Choppiness Index carries no directional information, it's typically used as a filter alongside a directional indicator rather than as a standalone buy/sell trigger: a low reading can support using trend-following tools, while a high reading can support favoring range or mean-reversion approaches instead.
Turning points
Some traders watch for the index rising toward its high range and then turning down as an early signal that a period of consolidation may be giving way to a new trend, though, as with any single indicator. This is a probabilistic read, not a confirmed signal on its own.
Standard and Alternative Settings
| Period (n) | Responsiveness | Common use |
|---|---|---|
| 7 | Faster, noisier | Shorter-term/intraday reads |
| 14 | Balanced (default) | General-purpose swing analysis, matches the standard ATR period |
| 30 | Slower, smoother | Longer-term regime classification |
Limitations
- No directional information, a low reading confirms trendiness but says nothing about whether that trend is up or down, so it can't be used alone to decide a trade direction.
- Lagging by construction, every input (ATR sum, period high, period low) is drawn from completed past bars, so the index confirms a regime that's already underway rather than predicting a shift in advance.
- Sensitive to period choice, a shorter lookback reacts faster but produces noisier swings between choppy and trending readings; a longer lookback smooths that out at the cost of responsiveness.
- Threshold conventions vary, there's no single universally agreed "choppy" or "trending" cutoff; commonly cited levels differ by source and platform default.
Common Mistakes
- Using it as a standalone entry signal, since it has no directional component, a reading alone doesn't tell a trader whether to go long or short.
- Ignoring the period mismatch with other indicators, comparing a 14-period Choppiness Index against a differently-configured trend indicator can produce readings that appear to disagree simply because they're measuring different lookback windows.
- Treating a moderate mid-range reading as meaningful, values well away from either extreme carry less interpretive weight than readings clearly near 0 or 100.
A Regime Filter That Reports the Regime That Just Ended
The Choppiness Index measures whether recent price movement has been directional or sideways, which makes it a regime classifier rather than a signal. Its value lies in deciding which method to apply, since trend approaches and range approaches fail in each other's conditions.
Use it as a gate rather than an input to a trade decision. A reading indicating a ranging market suggests holding off on breakout methods; one indicating a trending market suggests holding off on mean-reversion methods. That is a genuine improvement over applying one approach continuously.
The mistake is expecting it to signal a transition. The measure is computed from a lookback window, so it reports the character of the period that has just passed and changes only after the new regime has persisted long enough to dominate the window. Transitions are exactly where it is least informative.
The thresholds are also conventions rather than derived values, and the appropriate boundary between choppy and trending differs by instrument and timeframe. A number that classifies one market sensibly will misclassify another, which means calibration against your own instrument is part of using the tool rather than an optional refinement.
Choppiness Index FAQs
What does the Choppiness Index measure?
The Choppiness Index measures whether a market is trending or moving sideways in a choppy, directionless range. It does not indicate which direction price is moving, only how much it is trending versus chopping.
Who created the Choppiness Index?
The Choppiness Index was developed by E.W. Dreiss. It compares the sum of Average True Range over a period against the total high-low range covered over that same period.
What is considered a high Choppiness Index reading?
Readings near 100 are commonly read as choppy, sideways conditions, and readings near 0 as strongly trending conditions. Some traders and platforms use the Fibonacci-derived levels of 61.8 and 38.2 as informal choppy/trending thresholds, but this is a commonly cited convention rather than a fixed rule, and exact default thresholds can vary by charting platform.
Does the Choppiness Index show market direction?
No. The Choppiness Index only measures the degree of trendiness versus choppiness in price action. It says nothing about whether that trend, if present, is up or down, traders pair it with a directional tool for that.
What is the standard period setting for the Choppiness Index?
A 14-period lookback is the most commonly cited default, matching the conventional Average True Range period, though the period is adjustable on most charting platforms.
Can the Choppiness Index be combined with other indicators?
Yes, because it only measures trendiness, not direction. It is commonly paired with a directional or momentum tool such as moving averages, MACD, or RSI so a trader can gauge both whether a trend exists and which way it points.
How does the index distinguish a trend from a range without using direction?
It compares the total distance price travelled during the period against the overall range covered. A trend moves persistently in one direction, so the distance travelled is close to the range. A choppy market covers a lot of distance while ending near where it started, so travelled distance far exceeds the range. Direction never enters the calculation, which is why the reading is identical for a strong advance and a strong decline.
What does an extreme low reading suggest about what comes next?
A very low reading indicates the period was strongly directional, and the common interpretation is that such conditions eventually give way to consolidation. That expectation is an inference about mean reversion in volatility regimes rather than something the calculation contains. Trends can persist well past a reading that appeared extreme, which is why the index is more useful as a description of the current regime than as a timing signal.
Does the index work the same way on intraday charts?
The calculation is timeframe-agnostic, but the interpretation shifts because intraday data contains more noise relative to directional movement. The index tends to register higher values on shorter timeframes for the same underlying market behaviour. Thresholds calibrated on daily data therefore rarely transfer, and the sensible approach is establishing what the typical range is on the timeframe being used.
References
- CMT Association: Technical Analysis Body of Knowledge and Research
- CFA Institute Research and Policy Center: Investment Research
- TA-Lib: Technical Analysis Function Library Documentation
- The Choppiness Index was developed by E.W. Dreiss and remains a widely referenced tool for classifying trending versus range-bound market conditions.
- SEC Investor.gov: Introduction to Investing