> ## 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.

# Moving averages

> ta.sma, ta.ema, ta.rma, ta.wma, ta.hma, ta.vwma, ta.alma, ta.swma, ta.linreg - trend smoothing functions.

## Overview

All moving average functions accept a `source` argument - either a `ctx.*` accessor, an `input.source()` result, or any `(offset?) => number | null` function. They return a scalar at the current bar.

## Functions

### `ta.sma(source, length)` - Simple moving average

Arithmetic mean over `length` bars.

```js theme={null}
onBar(() => {
  plot("SMA20", ta.sma(ctx.close, 20));
});
```

### `ta.ema(source, length)` - Exponential moving average

Exponentially weighted, with factor `α = 2 / (length + 1)`. Faster to react than SMA.

```js theme={null}
onBar(() => {
  plot("EMA9",  ta.ema(ctx.close, 9));
  plot("EMA21", ta.ema(ctx.close, 21));
});
```

### `ta.rma(source, length)` - Wilder smoothing

EMA with `α = 1 / length`. Also known as Wilder's Moving Average (RMA). Used internally by `ta.rsi` and `ta.atr`.

```js theme={null}
onBar(() => {
  const gain = math.max(ctx.close() - ctx.close(1), 0);
  plot("Smoothed gain", ta.rma(() => gain, 14));
});
```

### `ta.wma(source, length)` - Weighted moving average

Linearly weighted - most recent bar has the highest weight.

```js theme={null}
onBar(() => {
  plot("WMA14", ta.wma(ctx.close, 14));
});
```

### `ta.hma(source, length)` - Hull moving average

Reduces lag by combining WMAs. `HMA = WMA(2*WMA(n/2) - WMA(n), sqrt(n))`.

```js theme={null}
onBar(() => {
  plot("HMA20", ta.hma(ctx.close, 20));
});
```

### `ta.vwma(source, volume, length)` - Volume-weighted moving average

Weights each bar by its volume.

```js theme={null}
onBar(() => {
  plot("VWMA20", ta.vwma(ctx.close, ctx.volume, 20));
});
```

### `ta.alma(source, length, offset?, sigma?)` - Arnaud Legoux moving average

Gaussian-weighted. `offset` controls the phase (default `0.85`), `sigma` controls smoothing (default `6`).

```js theme={null}
onBar(() => {
  plot("ALMA", ta.alma(ctx.close, 20, 0.85, 6));
});
```

### `ta.swma(source)` - Symmetrically weighted moving average

Fixed-length 4-bar average with weights `[1, 2, 2, 1] / 6`.

```js theme={null}
onBar(() => {
  plot("SWMA", ta.swma(ctx.close));
});
```

### `ta.linreg(source, length)` - Linear regression value

Returns the current value on the linear regression line fitted to the last `length` bars.

```js theme={null}
onBar(() => {
  plot("LinReg20", ta.linreg(ctx.close, 20));
});
```

## Ribbon example

```js theme={null}
const lengths = [8, 13, 21, 34, 55];

plot("EMA8",  null, { color: "#22c55eFF" });
plot("EMA13", null, { color: "#84cc16FF" });
plot("EMA21", null, { color: "#eab308FF" });
plot("EMA34", null, { color: "#f97316FF" });
plot("EMA55", null, { color: "#ef4444FF" });

onBar(() => {
  plot("EMA8",  ta.ema(ctx.close, 8));
  plot("EMA13", ta.ema(ctx.close, 13));
  plot("EMA21", ta.ema(ctx.close, 21));
  plot("EMA34", ta.ema(ctx.close, 34));
  plot("EMA55", ta.ema(ctx.close, 55));
});
```

## Related pages

<CardGroup cols={2}>
  <Card title="Oscillators" href="/ta/oscillators">
    RSI, MACD, Stochastic and more.
  </Card>

  <Card title="Crossovers" href="/ta/crossovers">
    Detect when two MAs cross.
  </Card>

  <Card title="Bar context" href="/essentials/bar-context">
    Source function shape reference.
  </Card>
</CardGroup>