Momentum
Compares current price with price a fixed number of periods ago.
Start with the input, not the story.
Absolute or ratio-based directional change over the lookback.
Plain-language formula
Platform implementations can differ in price input, smoothing, indexing and rounding. Record the exact settings and provider before comparing results.
Where it may help
Simple directional state and acceleration studies.
Where it struggles
Noisy short windows and strategies without a separate risk model.
Add a different measurement.
A complementary tool should answer a different question, such as volatility, regime or position risk. Test the base rule before testing the combination.
The shortcut to avoid
Confusing high momentum with low-risk entry.
A testable next step
Measure results by momentum decile rather than selecting one threshold first.