Elder Bull/Bear Power

How far buyers pushed the high above the average, and how far sellers pushed the low below it.

What it measures

Alexander Elder’s Bull Power is the bar’s high minus an EMA of the close; Bear Power is the low minus the same EMA. Both are in price units.

How traders read it

Elder used them with a trend filter: in an uptrend, buy when Bear Power is negative but rising; in a downtrend, sell when Bull Power is positive but falling.

Formula

Bull Power = high − EMA(periods)
Bear Power = low − EMA(periods)

Settings and output

Call: elderBBPower(periods)

Setting	Chart default
`periods`: Periods	13

What you get: a list of 2, in this order: 1. a number (“Elder Bull Power”); 2. a number (“Elder Bear Power”).

Warm-up: with elderBBPower(13), it asks for 13 bars of history and a run-up of 26, and its first value came on bar 14 of the example data.

Chart

Elder Bull/Bear Power drawn by its own code on example prices

The prices are made up, hourly, and the same on every page, so the chart shows how the indicator behaves, not how a market behaved.

In an algorithm

let previousBear;

function onIntervalClose() {
  const power = elderBBPower(13);
  const bear = power[1];
  const rising = previousBear !== undefined && bear > previousBear;
  if (OPEN_POSITIONS_COUNT === 0 && ema(13) > ema(50) && bear < 0 && rising) {
    openPosition("BUY", { quantity: 10000, stopLossPips: 25, takeProfitPips: 50 });
  }
  previousBear = bear;
}