TradeIncremental

One trade on an instrument. Direction: Kraken → client

ID	Field	Type	Encoding	Presence	Description
1	`instrumentId`	`InstrumentId`	field	required
2	`transactTime`	`TimestampNs`	field	required	Time the trade occurred at the source
4	`tradeSeq`	`uint64`	field	required	Contiguous per-instrument trade sequence, starting at one
5	`tradeId`	`TradeId`	field	required
6	`orderId`	`OrderId`	field	required	Aggressor order ID for this trade
7	`price`	`Price`	field	required
8	`quantity`	`Quantity`	field	required
9	`aggressorSide`	`AggressorSide`	field	optional
10	`ordType`	`OrdTypeMD`	field	optional

Every message is preceded by the standard SBE messageHeader (blockLength, templateId, schemaId, version). See encodings.