Reading Backtest Results

When a backtest finishes, the backtest page shows the profit curve, statistics, status information, logs and account information.

Profit curve

The profit curve consists of the values the strategy records with LogProfit() (LogProfit). If the strategy never calls LogProfit(), there is no profit curve and the statistics below, which depend on that series, cannot be computed; only the final assets in the account information remain. The profit and max_drawdown returned by the MCP tool get_backtest also come from LogProfit().

Statistics

The statistics are computed from the profit series profits (each element [timestamp, profit]) and the initial assets totalAssets with the algorithm below:

yearDays is the number of days per year used for annualization, passed in by the backtest page. Note that daily returns are annualized by multiplying by yearDays rather than the usual √yearDays, so this Sharpe ratio should not be compared directly with values from other platforms.

Algorithm source:

            javascript
            
            
function returnAnalyze(totalAssets, profits, ts, te, period, yearDays) {
    // force by days
    period = 86400000
    if (profits.length == 0) {
        return null
    }
    var freeProfit = 0.03 // 0.04
    var yearRange = yearDays * 86400000
    var totalReturns = profits[profits.length - 1][1] / totalAssets
    var annualizedReturns = (totalReturns * yearRange) / (te - ts)

    // MaxDrawDown
    var maxDrawdown = 0
    var maxAssets = totalAssets
    var maxAssetsTime = 0
    var maxDrawdownTime = 0
    var maxDrawdownStartTime = 0
    var winningRate = 0
    var winningResult = 0
    for (var i = 0; i < profits.length; i++) {
        if (i == 0) {
            if (profits[i][1] > 0) {
                winningResult++
            }
        } else {
            if (profits[i][1] > profits[i - 1][1]) {
                winningResult++
            }
        }
        if ((profits[i][1] + totalAssets) > maxAssets) {
            maxAssets = profits[i][1] + totalAssets
            maxAssetsTime = profits[i][0]
        }
        if (maxAssets > 0) {
            var drawDown = 1 - (profits[i][1] + totalAssets) / maxAssets
            if (drawDown > maxDrawdown) {
                maxDrawdown = drawDown
                maxDrawdownTime = profits[i][0]
                maxDrawdownStartTime = maxAssetsTime
            }
        }
    }
    if (profits.length > 0) {
        winningRate = winningResult / profits.length
    }
    // trim profits
    var i = 0
    var datas = []
    var sum = 0
    var preProfit = 0
    var perRatio = 0
    var rangeEnd = te
    if ((te - ts) % period > 0) {
        rangeEnd = (parseInt(te / period) + 1) * period
    }
    for (var n = ts; n < rangeEnd; n += period) {
        var dayProfit = 0.0
        var cut = n + period
        while (i < profits.length && profits[i][0] < cut) {
            dayProfit += (profits[i][1] - preProfit)
            preProfit = profits[i][1]
            i++
        }
        perRatio = ((dayProfit / totalAssets) * yearRange) / period
        sum += perRatio
        datas.push(perRatio)
    }

    var sharpeRatio = 0
    var volatility = 0
    if (datas.length > 0) {
        var avg = sum / datas.length;
        var std = 0;
        for (i = 0; i < datas.length; i++) {
            std += Math.pow(datas[i] - avg, 2);
        }
        volatility = Math.sqrt(std / datas.length);
        if (volatility !== 0) {
            sharpeRatio = (annualizedReturns - freeProfit) / volatility
        }
    }

    return {
        totalAssets: totalAssets,
        yearDays: yearDays,
        totalReturns: totalReturns,
        annualizedReturns: annualizedReturns,
        sharpeRatio: sharpeRatio,
        volatility: volatility,
        maxDrawdown: maxDrawdown,
        maxDrawdownTime: maxDrawdownTime,
        maxAssetsTime: maxAssetsTime,
        maxDrawdownStartTime: maxDrawdownStartTime,
        winningRate: winningRate
    }
}

Downloading data

• Status bar data: after the backtest finishes, click "Download Table" at the top right of the "Status" panel to download the final status bar data as a CSV file.
• Log data: click "Download Table" at the top right of the "Logs" panel to download the backtest logs as a CSV file.