Momentum Bands

The indicator plots three lines on the chart — an upper band, a moving average, and a lower band — forming an envelope around price.

On each bar it computes a momentum value by subtracting the price n bars ago from the current price (where n is the momentum period). This captures how fast price is moving, not just where it is.

It then looks back over the last period bars and sums up the squared momentum values. The square root of that average gives a momentum-based standard deviation — essentially, how volatile or forceful recent price moves have been.

The center line is a simple moving average of price. The upper and lower bands are placed multiplier × deviation above and below that average. Wide bands = high momentum/volatility; tight bands = calm, slow-moving price.

The non-repaint design comes from processing bars incrementally ( prev_calculated ) and avoiding any forward-looking references — each bar's values are locked to the close of that confirmed bar.