Hi @ming.cheng

As per the above replies and the article, the FieldList object contained within each map entry of an MBP payload does not have BID or ASK fields - therefore the question of 1 BID or 1 ASK does not make sense.

Each Map entry would only contains field like the following:

Fields":{
            "ACC_SIZE":22415,
            "LV_TIM_MS":53520032,
            "NO_ORD":7,
            "ORDER_PRC":106.68,
            "ORDER_SIDE":"ASK"
          },

As you will note, there is no BID or ASK field. The ORDER_SIDE field would indicate whether the order is a BID order or an ASK order.

As it is an order book, each entry represents orders - i.e. the number of buy orders or sell orders at the specified ORDER_PRC. Therefore, the idea of a single entry representing both BID and ASK orders does not make sense.

Furthermore, if you look at the Data Dictionary files (RDMFieldDictionary + enumtype.def) the ORDER_SIDE field is an enumerated field

ORDER_SIDE "ORDER SIDE" 3428 NULL ENUMERATED 3 ( 3 ) ENUM 1

and the valid Enum values for the field are:

! VALUE DISPLAY MEANING
! ----- ------- -------
0 " " undefined
1 "BID" Bid
2 "ASK" Ask

Hi,

Please see the answer in the original thread post.

Hi @ming.cheng

Are your questions related to MarketPrice (MP) or MarketByPrice(MBP) ?

MBP represents a Market Depth Aggregated Order Book i.e. a Collection of orders for an instrument grouped by Price point i.e. multiple orders per ‘row’ of data.

If you wish to understand the MBP data format please see the following article - the introduction contains some useful information - How to Sort & Process Level 2 Orderbook Data using EMA C++ API | Refinitiv Developers

As you will note from the above article, an MBP message (Refresh or Update) can contain multiple BID and or ASK prices - as they don't use the BID and ASK fields.

Hi @ming.cheng

Please read the above article which explains the format of the data. Also as mentioned earlier there is no BID or ASK field in the payload of an MBP map entry, so I don't understand your question about the BID and ASK fields.

A Refresh message Map could contain the following (a short extract)

and so on for the complete order book. As you can see the field names rename the same, ORDER_SIDE field indicates whether the order is an ASK or BID side.

And then an Update message Map could contain the following:

"Map":{
      "Entries":[
        {
          "Action":"Update",
          "Fields":{
            "ACC_SIZE":7491,
            "LV_TIM_MS":53520071,
            "NO_ORD":3,
            "ORDER_PRC":106.64,
            "ORDER_SIDE":"BID"
          },
          "Key":"MTA2LjY0Qg=="
        },
        {
          "Action":"Update",
          "Fields":{
            "ACC_SIZE":16254,
            "LV_TIM_MS":53520071,
            "NO_ORD":5,
            "ORDER_PRC":106.62,
            "ORDER_SIDE":"BID"
          },
          "Key":"MTA2LjYyQg=="
        },
        {
          "Action":"Update",
          "Fields":{
            "ACC_SIZE":22415,
            "LV_TIM_MS":53520032,
            "NO_ORD":7,
            "ORDER_PRC":106.68,
            "ORDER_SIDE":"ASK"
          },
          "Key":"MTA2LjY4QQ=="
        }
      ],
      "KeyType":"Buffer",
      "Summary":{
        "Fields":{
          "SEQNUM":20174992,
          "TIMACT_MS":53520071
        }
      }
    }

Actually it's my bad. Everytime when read an Exchange/broker's tech document, I feel almost 99.99% it should this or that. Howeve I still prefer to play a safe game to confirm with the source directly. No shame no harm.

Come to this particular question, I thought it should be quite straightforward that for any MBP FieldList data, it should only contain one side FIDs. Should your above sample have confirmed my conclusion?