STOCH (Stochastic Oscillator)

The Stochastic Oscillator compares a closing price to its price range over a given period. It produces two lines, %K and %D, oscillating between 0 and 100.

Declaration

function init(ctx) {
  ctx.indicator('stoch', 'STOCH', { kPeriod: 14, dPeriod: 3 });
}

Options

Option	Type	Default	Description
`kPeriod`	`number`	14	%K lookback period
`dPeriod`	`number`	3	%D smoothing period (SMA of %K)

Output

Returns an object with two series, accessed via underscore naming:

Property	Description
`k`	%K line (fast stochastic)
`d`	%D line (smoothed %K)

Accessing Values

function onBar(ctx, i) {
  const k = ctx.ind.stoch_k[i];
  const d = ctx.ind.stoch_d[i];
}

Use Cases

Overbought / Oversold

function onBar(ctx, i) {
  const k = ctx.ind.stoch_k[i];
  const d = ctx.ind.stoch_d[i];
  
  // Buy when %K crosses above %D in oversold territory
  if (k < 20 && q.crossOver(ctx.ind.stoch_k, ctx.ind.stoch_d, i)) {
    ctx.order.market('ASSET', 1, { signal: 'buy', reason: 'stoch_oversold_cross' });
  }
  
  // Sell when %K crosses below %D in overbought territory
  if (k > 80 && q.crossUnder(ctx.ind.stoch_k, ctx.ind.stoch_d, i)) {
    ctx.order.close('ASSET', { signal: 'sell', reason: 'stoch_overbought_cross' });
  }
}

Value Ranges

Range	Interpretation
0 - 20	Oversold
20 - 80	Neutral
80 - 100	Overbought

Calculation

$$%K = \frac{Close - Lowest Low}{Highest High - Lowest Low} \times 100$$

$%D = SMA(%K, dPeriod)$

Stochastic RSI - Stochastic applied to RSI
RSI - Momentum oscillator
Williams %R - Similar range-based oscillator