Momentum strategies rely on indicators that measure the speed, direction, and strength of price movements. Unlike oscillators used in mean reversion (which identify extremes for reversal), momentum indicators are designed to confirm that a trend is in progress and has the strength to continue.
MACD (Moving Average Convergence Divergence)
MACD is one of the most widely used momentum indicators. It captures the relationship between two exponential moving averages to identify shifts in trend direction and momentum strength.
Signal Interpretation
- MACD crosses above Signal — Bullish momentum is accelerating. This is the classic MACD buy signal.
- MACD crosses below Signal — Bearish momentum is accelerating. Potential sell or short signal.
- Histogram expanding — Momentum is strengthening in the current direction.
- Histogram contracting — Momentum is weakening, a potential early warning of reversal.
- Zero line crossover — MACD crossing above zero means the fast EMA is above the slow EMA, confirming an uptrend at the moving average level.
When price makes a new high but MACD makes a lower high, this is bearish divergence — momentum is fading even as price pushes higher. The reverse (price new low, MACD higher low) is bullish divergence. Divergence does not predict the timing of a reversal, but it warns that the current trend is losing conviction.
Platform Usage
In the Momentum Strategy Builder and Overlay/Builder, MACD is available as a primary entry indicator. You can configure the fast, slow, and signal periods, and set entry conditions on the MACD line, signal line, histogram, or zero crossover. The histogram is particularly useful as a momentum strength filter.
ADX (Average Directional Index)
ADX measures trend strength on a scale from 0 to 100, regardless of direction. The accompanying +DI and -DI lines indicate whether the trend is bullish or bearish.
- ADX < 20 — No significant trend. Market is range-bound. Avoid momentum entries.
- ADX 20-25 — Emerging trend. A potential setup is forming but not yet confirmed.
- ADX 25-40 — Strong trend. Optimal environment for momentum strategies.
- ADX 40-50 — Very strong trend. Highly profitable but may be approaching exhaustion.
- ADX > 50 — Extreme trend. Rare condition; be cautious of impending reversal.
ADX with Directional Movement
ADX alone tells you how strong the trend is but not the direction. Use the +DI and -DI components for direction:
- +DI above -DI — The trend is bullish. Buyers are dominant.
- -DI above +DI — The trend is bearish. Sellers are dominant.
- DI crossover — When +DI crosses above -DI, it signals a shift from bearish to bullish momentum (and vice versa).
The strongest momentum signal occurs when ADX is rising above 25 AND +DI is above -DI (for long trades). This confirms both the presence and direction of a strong trend. The Momentum Scanner uses this combination to rank S&P 500 stocks.
ROC (Rate of Change)
Rate of Change is the most direct momentum measure — the percentage change in price over a fixed lookback period. Its simplicity is its strength: no smoothing, no parameter-heavy calculations, just raw momentum.
Lookback Period Selection
- Short-term (5-10 days) — Captures rapid momentum bursts. More signals but more noise.
- Medium-term (20-50 days) — Captures the "sweet spot" for swing trading momentum. Fewer false signals.
- Long-term (100-250 days) — Captures secular trends. Very few signals but high conviction.
The optimal lookback depends on your trading timeframe. Research consistently shows that 3-12 month momentum (approximately 60-250 trading days) has the strongest predictive power for future returns, while very short-term (under 1 week) and very long-term (over 12 months) momentum tends to reverse.
Aroon Indicator
Aroon measures how recently the highest high and lowest low occurred within a lookback period. It identifies whether an asset is trending and how strong that trend is.
Signal Interpretation
- Aroon Up above 70 — Strong uptrend. New highs are being made frequently.
- Aroon Down above 70 — Strong downtrend. New lows are being made frequently.
- Aroon Oscillator above +50 — Bullish momentum dominates.
- Aroon Oscillator below -50 — Bearish momentum dominates.
- Aroon Up crosses above Aroon Down — Trend is shifting from bearish to bullish.
Aroon captures a fundamental aspect of trending markets: in a genuine uptrend, the most recent high should be very recent. If the highest high occurred 20 days ago in a 25-day window, the uptrend has likely stalled or reversed. This time-based approach to momentum is complementary to price-based indicators like MACD and ROC.
TSI (True Strength Index)
TSI applies double exponential smoothing to the price change, creating a momentum oscillator that is less noisy than single-smoothed alternatives. It ranges from -100 to +100.
Signal Interpretation
- TSI above zero — Positive momentum. The trend is upward.
- TSI below zero — Negative momentum. The trend is downward.
- TSI crossing zero — A trend direction change. Zero crossovers are significant momentum shifts.
- TSI signal line crossover — Like MACD, TSI can be paired with a signal line for faster entry/exit timing.
PPO (Percentage Price Oscillator)
PPO is the percentage-based version of MACD. While MACD shows the absolute difference between two EMAs, PPO expresses this as a percentage, making it comparable across stocks with different price levels.
PPO is particularly useful when comparing momentum across different stocks. A PPO of 2% on a $10 stock and a $500 stock represents the same relative momentum strength, whereas their MACD values would be vastly different.
Vortex Indicator
The Vortex Indicator captures positive and negative trend movement by measuring the distance between the current high and the prior low (positive vortex, +VI) versus the current low and the prior high (negative vortex, -VI).
Signal Interpretation
- +VI crosses above -VI — Bullish trend initiation. Upward momentum has overtaken downward movement.
- -VI crosses above +VI — Bearish trend initiation.
- Wide spread between +VI and -VI — Strong directional conviction.
TRIX (Triple Exponential Average)
TRIX applies triple exponential smoothing to price, then calculates the rate of change of the result. This heavy smoothing filters out virtually all short-term noise, leaving only significant trend changes.
TRIX is best used for identifying major trend changes rather than short-term entries. When TRIX crosses above zero, it confirms a significant shift to bullish momentum. Its heavy smoothing means it produces fewer signals but with higher conviction.
- MACD — Best all-around momentum indicator. Good balance of sensitivity and reliability.
- ADX — Best for confirming whether a trend exists before entering. Use as a filter, not a signal.
- ROC — Best for simple, interpretable momentum measurement. Good for screening.
- Aroon — Best for detecting trend initiations and measuring how recently new highs/lows occurred.
- TSI — Best for noisy stocks where you need heavy smoothing to see the underlying trend.
- PPO — Best for comparing momentum across stocks with different price levels.
- Vortex — Best for capturing directional shifts using high/low relationships.
- TRIX — Best for long-term trend confirmation with minimal false signals.
All momentum indicators lag price to some degree because they are derived from past data. Faster indicators (short-period ROC, MACD with tight parameters) produce earlier signals but more false ones. Slower indicators (TRIX, long-period ADX) produce later signals but with higher accuracy. There is no perfect setting — the tradeoff between speed and reliability is fundamental.