Prev Day ±1% Boundary

This indicator plots dynamic intraday price bands based on the previous day’s close. It calculates a reference price using yesterday’s daily close and draws:

An upper boundary at +1% above the previous close

A lower boundary at –1% below the previous close

These levels are shown as horizontal lines across all intraday bars, with an optional shaded zone between them.

How to use:

Use the boundaries as intraday reference levels for potential support, resistance, or mean-reversion zones.

When price trades near the upper band, it may indicate short-term extension to the upside relative to the prior close.

When price trades near the lower band, it may indicate short-term extension to the downside.

The shaded region between the lines highlights a ±1% normal fluctuation zone around the previous day’s closing price.

This tool is especially useful for intraday traders on indices like SPX, providing quick visual context for how far price has moved relative to the prior session’s close.