What is a repainting indicator
A repainting indicator is a chart tool whose values or signals on past bars change after new price data arrives. A bar is a single candle or period on the chart. When you look at history, you see the final, corrected version, not what the indicator showed at the time.
Not every change is repainting. Three situations look similar but mean different things:
| Situation | What happens | Is it a problem? |
|---|---|---|
| Live-bar update | The value on the bar that is still open moves with price | Normal for almost every indicator. It becomes a problem only if you act before the bar closes |
| Back-painting | A signal appears later but is drawn on an earlier bar | Yes. The chart hides the delay |
| True repaint | Values on closed bars are recalculated and redrawn | Yes. History no longer matches what you saw live |
Ready to try it on a real or demo account?
Partner link · trading carries a high risk of loss
Indicators that repaint or back-paint
- ZigZag: the last leg is redrawn until price moves far enough the other way. Old swing points can disappear.
- Fractals: a fractal needs bars on both sides of it, so the arrow is confirmed later but drawn on the earlier bar.
- Centred moving averages and centred bands: they use bars on both sides of each point, so the latest part is recalculated as new bars come in.
- Linear regression channel: the whole channel is refitted when the anchor or the latest bar changes.
- Multi-timeframe indicators: a higher-timeframe value shown on a lower-timeframe chart keeps changing until the higher bar closes, but history shows only its final value.
- Custom "arrow" indicators that look ahead in their code, or use a negative shift, which places future data onto past bars.
- Ichimoku lagging span: it is plotted back in time by design. It does not repaint, but it can mislead if you read it as current information. See Ichimoku.
A drawn example
The chart below is an illustration, not real prices.
On the finished chart the arrow sits exactly at the low and looks perfect. At the moment that low formed, the indicator showed nothing. The arrow was added only after price had already risen.
How repainting fools backtests
A backtest checks a set of rules against historical data. Repainting breaks it in several ways:
- Visual backtesting on a finished chart counts signals that did not exist in real time. Entries appear at tops and bottoms, so the results look far better than live trading.
- Look-ahead in code lets the rule use data from bars that had not formed yet. Any result built on that is invalid.
- Higher-timeframe data on lower-timeframe tests gives the test the closing value of the higher bar long before it was known.
- Missing signals: signals that appeared live and were later erased never reach the test, and those are often the losing ones.
The result is a strategy that looks strong in testing and then behaves very differently on a live account. Leveraged forex and CFD trading can lose money fast. Trusting a repainted backtest adds a hidden risk on top of that. See risk management.
How to check for a non repainting indicator
A non repainting indicator fixes its value once a bar closes. SMA, EMA, RSI, MACD and ATR work this way when you read them on closed bars. To test any indicator:
- Attach it to a chart and take a screenshot. Come back after many bars and compare the same area.
- Run it in the visual mode of the MetaTrader strategy tester and watch whether arrows appear late or move.
- Watch it live on a demo account for a while before relying on it.
- Base rules only on values from closed bars.
- Read the source code of custom indicators and look for future bar references or negative shifts.
For more on signal timing, see leading vs lagging indicators and technical analysis.
Frequent questions
Is every indicator that moves on the current bar repainting?
No. The open bar always changes with price. Repainting means values on closed bars change, or signals are drawn on earlier bars than when they appeared.
Is ZigZag useless because it repaints?
It is useful for marking past swings and studying market structure. It is not suitable as a live entry signal, because its last leg is not final.
Do Fractals repaint?
A confirmed fractal stays in place, but it is drawn on a bar earlier than the moment it was confirmed. Treat the signal as known only after the confirming bars have closed.
Can a non repainting indicator still give losing trades?
Yes. A stable indicator only means its history is honest. It does not predict price, and no indicator removes the risk of loss.
How can I tell if a paid indicator repaints?
Test it yourself with screenshots, the strategy tester's visual mode and a demo account. Be cautious of sellers who show only finished historical charts.