Pre-market range

A custom indicator created by James on TrendSpider. You can import this custom indicator into your TrendSpider account. Don't have TrendSpider? Create an account first, then import the custom indicator.

This is a simple indicator that plots the high and low of pre market session as horizontal lines on the chart making it easy to see the pre-market range on any timeframe. TEST

Source code

This indicator had been implemented by James in JavaScript on TrendSpider. Check out the developer documentation to learn more about JS on TrendSpider.

describe_indicator('Pre-market range');
//    30 is the highest time frame which still has candles not overlapping with
//    the market session
const extHoursData = await request.history(constants.ticker, '30', { ext_session: true });
const preMarketRangeByDay = {};
//    first, we compute { high, low } of pre-market
//    per each day we have in our ext data session
for (let extHoursIndex = 0; extHoursIndex < extHoursData.time.length; extHoursIndex += 1) {
    const sessionAtCandle = session_of(
        extHoursData.time[extHoursIndex],
        constants.resolution,
        constants.ext_session_premarket
    );
    const dayOfCandle = sessionAtCandle.session;
    if (!preMarketRangeByDay[dayOfCandle]) {
        preMarketRangeByDay[dayOfCandle] = {
            high: extHoursData.high[extHoursIndex],
            low: extHoursData.low[extHoursIndex]
        };
    }
    else {
        preMarketRangeByDay[dayOfCandle].high = Math.max(preMarketRangeByDay[dayOfCandle].high, extHoursData.high[extHoursIndex]);
        preMarketRangeByDay[dayOfCandle].low = Math.min(preMarketRangeByDay[dayOfCandle].low, extHoursData.low[extHoursIndex]);
    }
}
const rangeHigh = series_of(null);
const rangeLow = series_of(null);
const lastSession = session_of(time[time.length - 1], constants.resolution);
//    now we assigning "pre-market high/low range" to each candle on the chart
for (let candleIndex = 0; candleIndex < time.length; candleIndex += 1) {
    const sessionAtCandle = session_of(time[candleIndex], constants.resolution);
    const isLastSession = sessionAtCandle.session == lastSession.session;
    const extHoursRange = preMarketRangeByDay[sessionAtCandle.session];
    if (isLastSession && extHoursRange) {
        rangeHigh[candleIndex] = extHoursRange.high;
        rangeLow[candleIndex] = extHoursRange.low;
    }
    if ( (rangeHigh[candleIndex] != rangeHigh[candleIndex - 1]) || rangeLow[candleIndex] != rangeLow[candleIndex - 1]) {
        rangeHigh[candleIndex - 1] = null;
        rangeLow[candleIndex - 1] = null;
    }
}
paint(rangeHigh, { style: 'ladder', color: 'black' });
paint(rangeLow, { style: 'ladder', color: 'black' });