New version of Dual Thrust Trading strategy
www.fmz.com
Again, our tech member has rewritten the famous DT strategy.

Shorter coding lines, better performance.

Easier to understand, easier to learn the logic of the strategy.

The original one is at: https://fmzquant.quora.com/Dual-Thrust-Trading-strategy

Here is the new version:

            
            
            
var STATE_IDLE = 0
var STATE_LONG = 1
var STATE_SHORT = 2
var State = STATE_IDLE
var LastBarTime = 0
var UpTrack = 0
var DownTrack = 0
var InitAccount = null

function GetPosition(posType) {
    var positions = exchange.GetPosition()
    for (var i = 0; i < positions.length; i++) {
        if (positions[i].Type === posType) {
            return [positions[i].Price, positions[i].Amount];
        }
    }
    return [0, 0]
}

function CancelPendingOrders() {
    while (true) {
        var orders = exchange.GetOrders()
        for (var i = 0; i < orders.length; i++) {
            exchange.CancelOrder(orders[i].Id)
            Sleep(500)
        }
        if (orders.length === 0) {
            break
        }
    }
}

function Trade(currentState, nextState) {
    var pfn = nextState === STATE_LONG ? exchange.Buy : exchange.Sell
    if (currentState !== STATE_IDLE) {
        exchange.SetDirection(currentState === STATE_LONG ? "closebuy" : "closesell")
        while (true) {
            var amount = GetPosition(currentState === STATE_LONG ? PD_LONG : PD_SHORT)[1]
            if (amount === 0) {
                break
            }
            pfn(nextState === STATE_LONG ? _C(exchange.GetTicker).Sell * 1.001 : _C(exchange.GetTicker).Buy * 0.999, amount)
            Sleep(500)
            CancelPendingOrders()
        }
        var account = exchange.GetAccount()
        LogProfit(_N(account.Stocks - InitAccount.Stocks, 3), "rate of return:", _N((account.Stocks - InitAccount.Stocks) * 100 / InitAccount.Stocks, 3) + '%')
    }
    exchange.SetDirection(nextState === STATE_LONG ? "buy" : "sell")
    while (true) {
        var pos = GetPosition(nextState === STATE_LONG ? PD_LONG : PD_SHORT)
        if (pos[1] >= AmountOP) {
            Log("Average price of position", pos[0], "Quantity:", pos[1])
            break
        }
        pfn(nextState === STATE_LONG ? _C(exchange.GetTicker).Sell * 1.001 : _C(exchange.GetTicker).Buy * 0.999, AmountOP-pos[1])
        Sleep(500)
        CancelPendingOrders()
    }
}

function onTick() {
    var records = exchange.GetRecords()
    if (!records || records.length <= NPeriod) {
        return
    }
    var Bar = records[records.length - 1]
    $.PlotRecords(records, 'K line')
    if (LastBarTime !== Bar.Time) {
        var HH = TA.Highest(records, NPeriod, 'High')
        var HC = TA.Highest(records, NPeriod, 'Close')
        var LL = TA.Lowest(records, NPeriod, 'Low')
        var LC = TA.Lowest(records, NPeriod, 'Close')
        var Range = Math.max(HH - LC, HC - LL)
        UpTrack = _N(Bar.Open + (Ks * Range), 3)
        DownTrack = _N(Bar.Open - (Kx * Range), 3)
        $.PlotHLine(UpTrack, 'UpTrack')
        $.PlotHLine(DownTrack, 'DownTrack')
        LastBarTime = Bar.Time
    }

    LogStatus("Price:", Bar.Close, "Up:", UpTrack, "Down:", DownTrack, "Date:", new Date())
    var msg
    if (State === STATE_IDLE || State === STATE_SHORT) {
        if (Bar.Close >= UpTrack) {
            msg  = 'Buying long trigger price: ' + Bar.Close + ' Upper rail:' + UpTrack
            Log(msg)
            Trade(State, STATE_LONG)
            State = STATE_LONG
            $.PlotFlag(Bar.Time, msg, 'long', 'flag', 'red') 
        }
    }

    if (State === STATE_IDLE || State === STATE_LONG) {
        if (Bar.Close <= DownTrack) {
            msg = 'Selling short trigger price: ' + Bar.Close + ' lower rail:' + DownTrack
            Log(msg)
            Trade(State, STATE_SHORT)
            $.PlotFlag(Bar.Time, msg, 'short', 'circlepin', 'green')
            State = STATE_SHORT
        }
    }
}

function main() {
    exchange.SetContractType("quarter")
    exchange.SetMarginLevel(10)
    if (exchange.GetPosition().length > 0) {
        throw "There can be no positions before the strategy is started."
    }
    CancelPendingOrders()
    InitAccount = exchange.GetAccount()
    while (true) {
        onTick()
        Sleep(500)
    }
}