What Is a Repainting Indicator?

Technical concept

Repainting broadly describes indicator output that can change as new information arrives or when historical bars are recalculated. The practical concern is whether what you saw in real time matches what the chart appears to show later.

Why it matters

A historical chart can look cleaner than the live experience if past signals move, disappear or are recalculated. That can create unrealistic expectations.

Questions to ask

• Does the script use information from an unfinished bar?
• Can past markers change after a bar closes?
• Does the vendor clearly document its behavior?
• Are screenshots historical illustrations or genuine live observations?

Repainting is not the only issue

Even a non-repainting tool can produce losing signals. Lag, market regime, spreads, slippage and risk management still matter.