A bit of thinking about the logic of digital currency futures trading

A bit of thinking about the logic of digital currency futures trading

The Problem Scenario

长久以来，数字货币交易所持仓API接口的数据延迟问题总是困扰着我。一直没有找到合适的处理方式，这个问题的场景我来复现下。通常合约交易所提供的市价单其实为对手价，所以有时候用这个所谓的“市价单”有些不靠谱。因此我们在写数字货币期货交易策略时，大部分用的是限价单。在每次下单后，我们要检查持仓，看看下单是不是成交了，并且持有了对应的仓位。问题就出在这个持仓信息上，如果订单成交了，交易所持仓信息接口（就是我们调用exchange.GetPosition时底层实际去访问的交易所接口）返回的数据应当是包含新开仓持仓信息的，但是交易所返回的数据如果是旧数据，即刚才下单的订单成交前的持仓信息，这样就出问题了。交易逻辑可能认为订单没有成交，继续下单。但是交易所下单接口并不延迟，反而成交很快，下单就成交。这样会造成一种严重的后果就是策略在一次触发开仓的操作时会不停的重复下单。

Practical experience

Because of this issue, I have seen a strategy that has been crazy to open multiple positions, fortunately due to the market crash, floating once above 10 BTC.

Trying to solve

• The first option It is possible to design the strategy to place orders only the next time, and the price of the order can be added to the price of the counterparty at the time, and eat the price of the counterparty at a certain depth. The advantage of doing this is that only the next order is placed, and not judged based on the information held. This avoids the problem of repeated orders, but sometimes it is possible that when the price changes are relatively large, the order can trigger the price limit mechanism of the exchange, and it is possible to add a large slip price that is still not done, and miss the opportunity.

• The second option With the exchange's single market price function, the FMZ price transfer-1 is the market price list, and the OKEX futures interface has been upgraded to support real market price lists.

• The third option We still use the previous trading logic, using the limit order order, but we add some tests in the trading logic to try to solve the problem caused by this position data delay. Testing whether the post-order order disappeared directly in the pending list without being revoked (two possibilities: 1 withdrawal, 2 transactions), detecting such a situation and again ordering the same amount as the previous order, at this time it is necessary to pay attention to whether the hold data is delayed, let the program enter the waiting logic, retrieve the hold information, or even continue to optimize, increase the number of triggers waiting, more than a certain number of times indicates that the hold interface data delay problem is serious, let this transaction logic end.

Design based on Scheme 3

// 参数
/*
var MinAmount = 1
var SlidePrice = 5
var Interval = 500
*/

function GetPosition(e, contractType, direction) {
    e.SetContractType(contractType)
    var positions = _C(e.GetPosition);
    for (var i = 0; i < positions.length; i++) {
        if (positions[i].ContractType == contractType && positions[i].Type == direction) {
            return positions[i]
        }
    }

    return null
}

function Open(e, contractType, direction, opAmount) {
    var initPosition = GetPosition(e, contractType, direction);
    var isFirst = true;
    var initAmount = initPosition ? initPosition.Amount : 0;
    var nowPosition = initPosition;
    var directBreak = false 
    var preNeedOpen = 0
    var timeoutCount = 0
    while (true) {
        var ticker = _C(e.GetTicker)
        var needOpen = opAmount;
        if (isFirst) {
            isFirst = false;
        } else {
            nowPosition = GetPosition(e, contractType, direction);
            if (nowPosition) {
                needOpen = opAmount - (nowPosition.Amount - initAmount);
            }
            // 检测directBreak 并且持仓未变的情况
            if (preNeedOpen == needOpen && directBreak) {
                Log("疑似仓位数据延迟，等待30秒", "#FF0000")
                Sleep(30000)
                nowPosition = GetPosition(e, contractType, direction);
                if (nowPosition) {
                    needOpen = opAmount - (nowPosition.Amount - initAmount);
                }
                /*
                timeoutCount++
                if (timeoutCount > 10) {
                    Log("连续10次疑似仓位延迟，下单失败！", "#FF0000")
                    break
                }
                */
            } else {
                timeoutCount = 0
            }
        }
        if (needOpen < MinAmount) {
            break;
        }
        
        var amount = needOpen;
        preNeedOpen = needOpen
        e.SetDirection(direction == PD_LONG ? "buy" : "sell");
        var orderId;
        if (direction == PD_LONG) {
            orderId = e.Buy(ticker.Sell + SlidePrice, amount, "开多仓", contractType, ticker);
        } else {
            orderId = e.Sell(ticker.Buy - SlidePrice, amount, "开空仓", contractType, ticker);
        }

        directBreak = false
        var n = 0
        while (true) {
            Sleep(Interval);
            var orders = _C(e.GetOrders);
            if (orders.length == 0) {
                if (n == 0) {
                    directBreak = true
                }
                break;
            }
            for (var j = 0; j < orders.length; j++) {
                e.CancelOrder(orders[j].Id);
                if (j < (orders.length - 1)) {
                    Sleep(Interval);
                }
            }
            n++
        }
    }

    var ret = {
        price: 0,
        amount: 0,
        position: nowPosition
    };
    if (!nowPosition) {
        return ret;
    }
    if (!initPosition) {
        ret.price = nowPosition.Price;
        ret.amount = nowPosition.Amount;
    } else {
        ret.amount = nowPosition.Amount - initPosition.Amount;
        ret.price = _N(((nowPosition.Price * nowPosition.Amount) - (initPosition.Price * initPosition.Amount)) / ret.amount);
    }
    return ret;
}

function Cover(e, contractType, opAmount, direction) {
    var initPosition = null;
    var position = null;
    var isFirst = true;

    while (true) {
        while (true) {
            Sleep(Interval);
            var orders = _C(e.GetOrders);
            if (orders.length == 0) {
                break;
            }
            for (var j = 0; j < orders.length; j++) {
                e.CancelOrder(orders[j].Id);
                if (j < (orders.length - 1)) {
                    Sleep(Interval);
                }
            }
        }

        position = GetPosition(e, contractType, direction)
        if (!position) {
            break
        }
        if (isFirst == true) {
            initPosition = position;
            opAmount = Math.min(opAmount, initPosition.Amount)
            isFirst = false;
        }

        var amount = opAmount - (initPosition.Amount - position.Amount)
        if (amount <= 0) {
            break
        }

        var ticker = _C(exchange.GetTicker)
        if (position.Type == PD_LONG) {
            e.SetDirection("closebuy");
            e.Sell(ticker.Buy - SlidePrice, amount, "平多仓", contractType, ticker);
        } else if (position.Type == PD_SHORT) {
            e.SetDirection("closesell");
            e.Buy(ticker.Sell + SlidePrice, amount, "平空仓", contractType, ticker);
        }

        Sleep(Interval)
    }

    return position
}

$.OpenLong = function(e, contractType, amount) {
    if (typeof(e) == "string") {
        amount = contractType
        contractType = e
        e = exchange
    }

    return Open(e, contractType, PD_LONG, amount);
}

$.OpenShort = function(e, contractType, amount) {
    if (typeof(e) == "string") {
        amount = contractType
        contractType = e
        e = exchange
    }

    return Open(e, contractType, PD_SHORT, amount);
};

$.CoverLong = function(e, contractType, amount) {
    if (typeof(e) == "string") {
        amount = contractType
        contractType = e
        e = exchange
    }

    return Cover(e, contractType, amount, PD_LONG);
};

$.CoverShort = function(e, contractType, amount) {
    if (typeof(e) == "string") {
        amount = contractType
        contractType = e
        e = exchange
    }

    return Cover(e, contractType, amount, PD_SHORT);
};


function main() {
    Log(exchange.GetPosition())
    var info = $.OpenLong(exchange, "quarter", 100)
    Log(info, "#FF0000")

    Log(exchange.GetPosition())
    info = $.CoverLong(exchange, "quarter", 30)
    Log(exchange.GetPosition())
    Log(info, "#FF0000")

    info = $.CoverLong(exchange, "quarter", 80)
    Log(exchange.GetPosition())
    Log(info, "#FF0000")
}

The template address is:https://www.fmz.com/strategy/203258

The way to call the template interface is the same as in the main function above.$.OpenLong，$.CoverLongI'm not going to lie. The template is a test version, and suggestions are welcome, and will continue to be optimized to address storage data latency.