> ## Documentation Index
> Fetch the complete documentation index at: https://docs.darvas.app/llms.txt
> Use this file to discover all available pages before exploring further.

# MACD histogram

> Standard MACD with histogram bars and signal/MACD line plots.

## What this builds

* MACD line (fast EMA - slow EMA)
* Signal line (EMA of MACD)
* Histogram (MACD - signal) with green/red coloring
* Zero line reference

## Full script

```js theme={null}
// overlay = false
const fastLen = input.int("Fast length",   12, { min: 1, group: "MACD" });
const slowLen = input.int("Slow length",   26, { min: 1, group: "MACD" });
const sigLen  = input.int("Signal length",  9, { min: 1, group: "MACD" });
const src     = input.source("Source", "close");

plot("MACD",     null, { color: "#22c55eFF", linewidth: 2 });
plot("Signal",   null, { color: "#f59e0bFF", linewidth: 2 });
plot("Histogram", null, {
  style: "histogram",
  colorUp:   "#22c55eCC",
  colorDown: "#ef4444CC",
});

hline(0, { color: "#6b728060" });

onBar(() => {
  const m = ta.macd(src, fastLen, slowLen, sigLen);
  if (na(m.macd)) return;

  plot("MACD",      m.macd);
  plot("Signal",    m.signal);
  plot("Histogram", m.hist);
});
```

## With divergence coloring

Color the MACD line based on whether it is above or below the signal:

```js theme={null}
// overlay = false
const src = input.source("Source", "close");

plot("MACD",     null, { linewidth: 2 });
plot("Signal",   null, { color: "#f59e0bFF" });
plot("Histogram", null, { style: "histogram" });

hline(0, { color: "#6b728060" });

const macdSeries = Series("macd-val");

onBar(() => {
  const m = ta.macd(src, 12, 26, 9);
  if (na(m.macd)) return;

  // Color MACD line based on trend
  const macdColor = m.macd > m.signal ? "#22c55eFF" : "#ef4444FF";
  // Note: per-bar color changes on 'plot' require re-registering with null each time
  // For simplicity, use a fixed color and rely on the histogram for the trend signal:

  plot("MACD",      m.macd);
  plot("Signal",    m.signal);
  plot("Histogram", m.hist);

  macdSeries.set(m.macd);
});
```

## Understanding the return value

`ta.macd` returns an object with three fields:

| Field    | Description                      |
| -------- | -------------------------------- |
| `macd`   | Fast EMA minus slow EMA          |
| `signal` | EMA of `macd` over `sigLen` bars |
| `hist`   | `macd` minus `signal`            |

All three are `NaN` during the warmup period (first `slowLen + sigLen - 2` bars approximately).

## Histogram color tip

The histogram uses `colorUp` and `colorDown` based on whether the value is positive or negative:

* `hist > 0` (MACD above signal) uses `colorUp`
* `hist <= 0` (MACD below signal) uses `colorDown`

```js theme={null}
plot("Histogram", null, {
  style: "histogram",
  colorUp:   "#22c55eCC",  // green bars when MACD > signal
  colorDown: "#ef4444CC",  // red bars when MACD < signal
});
```

## Related pages

<CardGroup cols={2}>
  <Card title="Oscillators" href="/ta/oscillators">
    ta.macd function reference.
  </Card>

  <Card title="Plot styles" href="/plotting/plot-styles">
    histogram style and colorUp/colorDown options.
  </Card>

  <Card title="NaN handling" href="/essentials/nan-handling">
    Why na(m.macd) check is needed during warmup.
  </Card>
</CardGroup>