EMA overlays
The EMA overlay draws up to three exponential moving averages on the footprint chart, each with its own period, color and width, from one shared price source (close, open, HL/2 or HLC/3).
Senzoukria · Documentation · Updated September 2026
Where to find it
- Where
- Chart → Indicators → Overlays → EMA
- Default
- Off; Source = Close; EMA 1 on (21), EMA 2 off (50), EMA 3 off (200)
- Convention
- First value = SMA of the first N inputs, then EMA = value·k + previous·(1−k), k = 2/(N+1)
- Warm-up
- No point before bar N−1; the line starts where the average is defined
What it does
The overlay computes an exponential moving average over the loaded bars and draws it on the price scale. The convention is the one used by ATAS, TradingView and MotiveWave: the first defined value is the simple average of the first N inputs, after which the recursive form applies with the smoothing factor k = 2/(N+1). Indices before N−1 hold no value, so the renderer starts the line where the average becomes meaningful rather than extrapolating.
Three lines share one Source setting. Close is the default; Open, HL/2 (the bar midpoint) and HLC/3 (the typical price) are the alternatives. Each line has its own enable switch, period, color and width, so a 21/50/200 stack or a single fast EMA are both a matter of toggles.
The EMA is keyed by candle time and cached per bar array: it is only recomputed when the bars change, following the same pattern as the session VWAP cache, so panning and zooming do not trigger a recalculation.
Settings
| Setting | Default | What it changes |
|---|---|---|
| Source | Close | Input series shared by the three lines: Close, Open, HL/2, HLC/3 |
| EMA 1 | On | Enable the first line |
| Period (line 1) | 21 bars (2–500) | Window of the first line |
| Color / Width (line 1) | #fbbf24 / 1.5 px | Stroke of the first line; width 1–4 in 0.5 steps |
| EMA 2 | Off | Enable the second line |
| Period (line 2) | 50 bars (2–500) | Window of the second line |
| Color / Width (line 2) | #e6e6e6 / 1.5 px | Stroke of the second line |
| EMA 3 | Off | Enable the third line |
| Period (line 3) | 200 bars (2–500) | Window of the third line |
| Color / Width (line 3) | #a855f7 / 2 px | Stroke of the third line |
How to use it
- Enable the overlay from the Indicators modal; EMA 1 at 21 bars is drawn immediately, the other two are opt-in.
- Keep the period small relative to the loaded history: a 200-bar EMA needs 200 loaded bars before its first point, and shows nothing on a shorter history.
- Use HLC/3 when you want the average to reflect the whole bar rather than its close, which is common on count bars where the close is arbitrary.
- Stack 21 / 50 / 200 by enabling the three lines; each keeps its own color and width, so the fast line can stay thinner than the slow one.
Limits or pitfalls
- The period is counted in bars, whatever the bar type. On tick, volume or range bars the EMA has no fixed time span.
- The overlay reads OHLC only; it does not use bid × ask levels and behaves identically on every data source.
- The library also offers EMA, DEMA, TEMA and ZLEMA as series studies with their own parameters; this page covers the three-line overlay of the Indicators modal.
Related pages
This page in other languages
Frequently asked questions
- Why does the EMA start late on the chart?
- The first value is the SMA of the first N bars, so nothing is drawn before bar N−1. A 200-period line needs 200 loaded bars before it appears.
- Can each line have its own source?
- No. Source is shared by the three lines; only the period, color, width and enable switch are per line.