The Don't Know Trade (DK) message notifies a trading partner that an electronically received execution has been rejected. This message can be thought of as an execution reject message.
This message has special utility when dealing with one-way execution reporting. If the initial Order Acknowledgment message (Execution Report with LastQty <32>=0 and OrdStatus <39>=New) does not match an existing order this message can be used to notify the broker of a potential problem order.
Note that the decision to DK an execution lies with the institution. Some of the mismatches listed in the DKReason <127> field may be acceptable and will not require a DK messages to be generated.
|Component Block - <StandardHeader>||Y||MsgType = Q|
|37||OrderID||Y||Broker Order ID as identified on problem execution|
|17||ExecID||Y||Execution ID of problem execution|
|Component Block - <Instrument>||Y||Insert here the set of "Instrument" (symbology) fields defined in "Common Components of Application Messages"|
|Component Block - <UndInstrmtGrp>||N||Number of underlyings|
|Component Block - <InstrmtLegGrp>||N||Number of Legs|
|Component Block - <OrderQtyData>||Y||Insert here the set of "OrderQtyData" fields defined in "Common Components of Application Messages"|
|32||LastQty||N||Required if specified on the ExecutionRpt|
|31||LastPx||N||Required if specified on the ExecutionRpt|
|354||EncodedTextLen||N||Must be set if EncodedText field is specified and must immediately precede it.|
|355||EncodedText||N||Encoded (non-ASCII characters) representation of the Text field in the encoded format specified via the MessageEncoding field.|
|Component Block - <StandardTrailer>||Y|