Topic: Detailed explanation of BitMEX pending order strategy (Read 150 times)

var ticker  = {price:0, buy:0, sell:0, time:0} //Ticker information, the latest price, "buy one" price, "sell one" price, update time
//Account information, respectively, position, buying and selling price, buying and selling quantity, position status, order Id
var info = {position:0, buyPrice:0, sellPrice:0, buyAmount:0, sellAmount:0, buyState:0, sellState:0, buyId:0, sellId:0}
var buyListId = []//Global variables, pre-emptive buying id list, will described below
var sellListId = []
var APIKEY = 'your api id' //Need to fill in the BitMEX API ID here. Note that it is not a key, which is required for websocket protocol authentication.
var expires = parseInt(Date.now() / 1000) + 10
var signature = exchange.HMAC("sha256", "hex", "GET/realtime" + expires, "{{secretkey}}")//The secretkey will be automatically replaced at the bottom level and does not need to be filled in.
var bitmexClient = Dial("wss://www.bitmex.com/realtime", 60)
var auth = JSON.stringify({args: [APIKEY, expires, signature], op: "authKeyExpires"})//Authentication information, otherwise you cannot subscribe to the account
bitmexClient.write(auth)
bitmexClient.write('{"op": "subscribe", "args": ["position","execution","trade:XBTUSD"]}')//Subscribed to positions, order execution and perpetual contract real-time transaction
while(true){
    var data = bitmexClient.read()
    if(data){
        bitmexData = JSON.parse(data)
        if('table' in bitmexData && bitmexData.table == 'trade'){
            data = bitmexData.data
            ticker.price = parseFloat(data[data.length-1].price)//The latest transaction price, will push multiple transactions at a time, take one will be ok
            //You can get the "buy one" and "sell one" price according to the direction of the latest transaction, without subscribing to the depth.
            if(data[data.length-1].side == 'Buy'){
                ticker.sell = parseFloat(data[data.length-1].price)
                ticker.buy = parseFloat(data[data.length-1].price)-0.5
            }else{
                ticker.buy = parseFloat(data[data.length-1].price)
                ticker.sell = parseFloat(data[data.length-1].price)+0.5
            }
            ticker.time =  new Date(data[data.length-1].timestamp);//Update time, can be used to determine the delay
        }
    }else if(bitmexData.table == 'position'){
        var position = parseInt(bitmexData.data[0].currentQty)  
        if(position != info.position){
            Log('Position change： ', position, info.position, '#FF0000@')//Position change Log, and pushed to WeChat, remove @ means Do not push
            info.position = position  
        }
        info.position  = parseInt(bitmexData.data[0].currentQty)  
    }
}

// Cancel all orders and reset global variables
function cancelAll(){
    exchange.IO("api","DELETE","/api/v1/order/all","symbol=XBTUSD")//Call IO extension revocation
    info = {position:0, buyPrice:0, sellPrice:0, buyAmount:0, sellAmount:0, buyState:0, sellState:0, buyId:0, sellId:0}
    buyListId = []
    sellListId = []
}
//placing alternate order
function waitOrders(){
    var orders = []
    if(buyListId.length<4){
        //When the number of inspections is insufficient, place another "bulk"
        for(var i=0;i<7;i++){
            //Due to BitMEX restrictions, the price can not be excessively excessive, the order quantity can not be too small, and the "execInst" parameter guarantees that only the market making transaction can be executed.
            orders.push({symbol:'XBTUSD', side:'Buy', orderQty:100, price:ticker.buy-400+i, execInst:'ParticipateDoNotInitiate'})
        }
    }
    if(sellListId.length<4){
        for(var i=0;i<7;i++){
            orders.push({symbol:'XBTUSD', side:'Sell', orderQty:100, price:ticker.buy+400+i, execInst:'ParticipateDoNotInitiate'})
        }
    }
    if(orders.length>0){
        var param = "orders=" + JSON.stringify(orders);
        var ids = exchange.IO("api", "POST", "/api/v1/order/bulk", param);//Bulk orders submitted here
        for(var i=0;i            if(ids.side == 'Buy'){
                buyListId.push(ids.orderID)
            }else{
                sellListId.push(ids.orderID)
            }
        }
    }
}
//Modify order function
function amendOrders(order, direction, price, amount, id){
    var param = "orders=" + JSON.stringify(order);
    var ret = exchange.IO("api", "PUT", "/api/v1/order/bulk", param);//Modify one order at a time
    //Modification occurs error
    if(!ret){
        var err = GetLastError()
        //overloaded unmodified strategy, need to recycle the order id
        if(err.includes('The system is currently overloaded')){
            if(id){
                if(direction == 'buy'){
                    buyListId.push(id)
                }else{
                    sellListId.push(id)
                }
            }
            Sleep(1000)
            return
        }
        //Illegal order status, indicating that the order to be modified has been completely executed
        else if(err.includes('Invalid ordStatus')){
            Log(order, direction)
            if(direction == 'buy'){
                info.buyId = 0
                info.buyState = 0
                info.buyAmount = 0
                info.buyPrice = 0
            }else{
                info.sellId = 0
                info.sellState = 0
                info.sellAmount = 0
                info.sellPrice = 0
            }
            //Since the push is not timely, update the position with the "rest" protocol here.
            pos = _C(exchange.GetPosition)
            if(pos.length>0){
                info.position = pos[0].Type == 0 ? pos[0].Amount : -pos[0].Amount
            }else{
                info.position = 0
            }
        }
        //Unknown error cannot be modified, all orders are cancelled, reset once
        else if(err.includes('Invalid orderID')){
            cancelAll()
            Log('Invalid orderID,reset once')
        }
        //Exceed the frequency limit, you can continue to try after hibernation
        else if(err.includes('Rate limit exceeded')){
            Sleep(2000)
            return
        }
        //The account is banned, all orders are revoked, and sleep is awaiting recovery for a long time.
        else if(err.includes('403 Forbidden')){
            cancelAll()
            Log('403,reset once')
            Sleep(5*60*1000)
        }
    }else{
        //Modify order successfully
        if(direction == 'buy'){
            info.buyState = 1
            info.buyPrice = price
            info.buyAmount = amount
        }else{
            info.sellState = 1
            info.sellPrice = price
            info.sellAmount = amount
        }
    }
}
//0.5 price change
function fixSize(num){
    if(num>=_N(num,0)+0.75){
        num = _N(num,0)+1
    }else if(num>=_N(num,0)+0.5){
        num=_N(num,0)+0.5
    }else{
        num=_N(num,0)
    }
    return num
}
//Trading function
function trade(){
    waitOrders()//Check if you need a replacement order
    var buyPrice = fixSize(ticker.buy-5) //For demonstration purposes only, specific transactions should be written by yourself.
    var sellPrice = fixSize(ticker.sell+5)
    var buyAmount =  500
    var sellAmount = 500
    //Modify from an alternate order when there is no order
    if(info.buyState == 0  && buyListId.length > 0){
        info.buyId = buyListId.shift()
        amendOrders([{orderID:info.buyId, price:buyPrice, orderQty:buyAmount}],'buy', group, buyPrice, buyAmount, info.buyId)
    }
    if(info.sellState == 0 && sellListId.length > 0){
        info.sellId = sellListId.shift()
        amendOrders([{orderID: info.sellId, price:sellPrice, orderQty:sellAmount}],'sell', group, sellPrice, sellAmount, info.sellId )
    }
    //Existing orders need to change price
    if(buyPrice !=  info.buyPrice && info.buyState == 1){
        amendOrders([{orderID:info.buyId, price:buyPrice, orderQty:buyAmount}],'buy', group, buyPrice, buyAmount)
    }
    if(sellPrice != info.sellPrice && info.sellState == 1){
        amendOrders([{orderID:info.sellId, price:sellPrice, orderQty:sellAmount}],'sell', group, sellPrice, sellAmount)
    }
}