Puzzled by setting order Size on futures

Hi there - got a small issue which could be down to my understanding of how to work with the various parameters required for creating a Futures order. On reading the documents, it would appear that i must first query the Contract in order to get the metadata related to min/max leverage allowed, plus data related to the Multiplier used. on querying this data, i receive a payload that has all of this metadata :

// symbol = “UNIUSDTM” var contract = await _clientFutures.FuturesApi.ExchangeData.GetContractAsync(symbol);

all good. However, I’m not entirely sure which data elements I should use as I’ve been getting varied results when applying the Multiplier found in the contract data. Below is my crude attempt to calculate the resulting size required for a fixed currency amount:

// dollarFunds =100m // bidPrice = 95.6 quantity = (dollarFunds / bidPrice / (contract.Data.Multiplier * leverageRate));

I also tried the simpler version of the below which worked in some cases, but like the other version, not all:

quantity = (dollarFunds / bidPrice * leverageRate);

I then use it as thus:

var orderBuy = await _clientFutures.FuturesApi.Trading.PlaceOrderAsync(
    symbol,
    orderSideAdd,
    Kucoin.Net.Enums.NewOrderType.Limit, leverageRate, quantity, bidPrice,
    Kucoin.Net.Enums.TimeInForce.GoodTillCanceled, remark: remark);

The above calc is obviously way wrong as it is fine for some contracts and wildly out for others.

I feel such an idiot, but what on earth am I doing wrong (either in terms of logic, or in terms of the data I’m using).

This is the final piece in a nice little leverage play that I’ve been working on successfully with minimum contract size, the missing puzzle piece now comes when applying hard scalable $$.

Hope you can help. jim

[jimtollan]

I figured it out. it was down to using the Multiplier in a particular way 😉

        quantity = Math.Round((dollarFunds / bidPrice * (leverageRate / contract.Data.Multiplier)),
            decimalPlaces, MidpointRounding.AwayFromZero);

hope this helps someone else. will add more detail later.

[jimtollan]

Sometimes you just gotta go with what works in the moment. Good work on getting it rolling and appreciate the additional info. I contacted the KuCoin API dev team and for posterity and any future folks here’s what I got:

SIZE
The size must be no less than the lotSize for the contract and no larger than the maxOrderQty. It should be a multiple number of lotSize, or the system will report an error when you place the order. Size indicates the amount of contract to buy or sell. Size is the number or lot size of the contract. Eg. the lot size of XBTUSDTM is 0.001 Bitcoin, the lot size of XBTUSDM is 1 USD.

"lotSize": 1,
"multiplier": 

All 1 is normal, because there is a multiplier field.

so the order value = lotSize * multiplier

We have to add more explanation about this to help doc  which we will do soon

well, if you happen to arrive at a nice little extension method or extended library that works against the Kucoin.Net library, then ping me the link if you share it. My version is definitely pretty ropey and too embarrassing to publicly expose!