ctx.series

Access historical price and volume data.

Available Series

Accessing Data

function onBar(ctx, i) {
  // Current bar
  const open = ctx.series.open[i];
  const high = ctx.series.high[i];
  const low = ctx.series.low[i];
  const close = ctx.series.close[i];
  const volume = ctx.series.volume[i];
  
  // Previous bars
  const prevClose = ctx.series.close[i - 1];
  const close5ago = ctx.series.close[i - 5];
}

Common Patterns

Bar range

const range = ctx.series.high[i] - ctx.series.low[i];
const bodySize = Math.abs(ctx.series.close[i] - ctx.series.open[i]);

Bullish/bearish bar

const isBullish = ctx.series.close[i] > ctx.series.open[i];
const isBearish = ctx.series.close[i] < ctx.series.open[i];

Price change

if (i > 0) {
  const change = ctx.series.close[i] - ctx.series.close[i - 1];
  const changePercent = change / ctx.series.close[i - 1] * 100;
}

Volume analysis

const avgVolume = q.avg(ctx.series.volume, 20, i);
const volumeRatio = ctx.series.volume[i] / avgVolume;

if (volumeRatio > 2) {
  // Volume spike - 2x average
}

New high/low detection

const highest20 = q.highest(ctx.series.high, 20, i - 1);
const lowest20 = q.lowest(ctx.series.low, 20, i - 1);

if (ctx.series.high[i] > highest20) {
  // New 20-bar high
}
if (ctx.series.low[i] < lowest20) {
  // New 20-bar low
}

Boundary Checks

Always check bounds when accessing previous bars:

function onBar(ctx, i) {
  if (i < 20) return; // Need 20 bars of history
  
  const ma20 = q.avg(ctx.series.close, 20, i);
}

Related

• onBar() — Where series is accessed
• Helper Functions — q.highest(), q.lowest(), etc.