--- title: "McGinley Dynamic: Formula, Meaning" description: "John McGinley's adaptive smoothing line that adjusts its own speed to the market. It moves faster when price is pulling away from the line and slower when..." canonical: https://www.getswoopr.com/indicators/trend/mcginley-dynamic/ source: "Swoopr Investment: https://www.getswoopr.com" --- ## Direct Answer > John McGinley's adaptive smoothing line that adjusts its own speed to the market. It moves faster when price is pulling away from the line and slower when price is close, in an attempt to avoid whipsaws. The line hugs price more closely than a simple moving average and is read the same way: price above a rising line for an uptrend, below a falling line for a downtrend. # McGinley Dynamic: Formula, Meaning, Signals, Examples and How to Use It ## How Is McGinley Dynamic Calculated? John McGinley's adaptive smoothing line that adjusts its own speed to the market. It moves faster when price is pulling away from the line and slower when price is close, in an attempt to avoid whipsaws. **Formula:** `MD(t) = MD(t-1) + (Price - MD(t-1)) / (k * N * (Price / MD(t-1))^4), with k commonly 0.6` **Inputs:** - Prices - Length N, comparable to a moving average period - Constant k (0.6 is the commonly used value) - A starting value, often the first price or an EMA **Worked example.** With a prior value of 100, a price of 102, N of 14 and k of 0.6, the next McGinley Dynamic value is 100.220. The inputs are illustrative numbers, not market data. **Reading it.** The line hugs price more closely than a simple moving average and is read the same way: price above a rising line for an uptrend, below a falling line for a downtrend. **Limits.** It is a recursive calculation, so early values depend on the starting point. The fourth-power term makes it behave unevenly in large price jumps, and it still lags. ## What is McGinley Dynamic? John McGinley's adaptive smoothing line that adjusts its own speed to the market. It moves faster when price is pulling away from the line and slower when price is close, in an attempt to avoid whipsaws. ## How to use McGinley Dynamic The line hugs price more closely than a simple moving average and is read the same way: price above a rising line for an uptrend, below a falling line for a downtrend. A reading alone is never a buy or sell signal; it needs context from price structure, volume, volatility and the broader market regime. ## Strengths - The step is divided by a factor containing the price-to-line ratio, so the speed of the line is re-set on every bar from current data. - Only the period N and the constant k are needed, so there are far fewer settings than in most adaptive averages. - Reproducible when the formula and data convention are fixed. ## Weaknesses and limitations - The constant k of 0.6 is a convention, and changing it alters the speed in a way not tied to any measured market property. - Because the ratio is price over line, adjustment is asymmetric: the line speeds up when price is below it and slows when price is above. - Correlated indicators can create false confidence by repeating the same underlying information. ## Editorial and risk note This page is educational content, not individualized investment advice. It should not imply guaranteed prediction, accuracy or outperformance. ## Frequently Asked Questions Is McGinley Dynamic a buy or sell signal? No. The line hugs price more closely than a simple moving average and is read the same way: price above a rising line for an uptrend, below a falling line for a downtrend. It is a recursive calculation, so early values depend on the starting point. A trade built on it still needs a trigger, an invalidation rule, a position size and realistic execution assumptions. What is the best setting for McGinley Dynamic? McGinley Dynamic takes these inputs: prices; length N, comparable to a moving average period; constant k (0.6 is the commonly used value). There is no universal best setting for the tunable ones, so test them across instruments, regimes and out-of-sample periods and favor stable parameter regions over one historical winner. Can McGinley Dynamic be used by itself? It is a recursive calculation, so early values depend on the starting point. The fourth-power term makes it behave unevenly in large price jumps, and it still lags. For that reason it is read next to measures of direction, participation, valuation, liquidity and risk, not alone. Does McGinley Dynamic work on every timeframe? The calculation (MD(t) = MD(t-1) + (Price - MD(t-1)) / (k * N * (Price / MD(t-1))^4), with k commonly 0.6) can be run on any bar size, but behavior is not portable: a reading on a five-minute chart describes a very different market window from the same reading on a daily chart. Validate the exact timeframe before relying on it. Why does McGinley Dynamic give false signals? The constant k of 0.6 is a convention, and changing it alters the speed in a way not tied to any measured market property. Because the ratio is price over line, adjustment is asymmetric: the line speeds up when price is below it and slows when price is above. Lag, noise and regime changes add to this, because market participants react to new information after the reading is calculated. How should McGinley Dynamic be backtested? Rebuild McGinley Dynamic from prices using point-in-time data, write the rules before testing, include delisted securities where relevant, model realistic fills and costs, reserve a validation sample and compare with a simpler baseline. S Swoopr Editorial Team The Swoopr Editorial Team produces independent investment education, research, and tools for understanding markets, evaluating opportunities, and managing risk. All content is educational only and does not constitute personalized investment advice. See our [editorial policy](https://www.getswoopr.com/legal/editorial-policy/) and [corrections policy](https://www.getswoopr.com/legal/corrections-policy/).