HistoricalMetricTarget

Target identity for a metric series. Populated fields depend on the query; unpopulated ids are null. Position queries set PositionId and account ids when resolvable. Leg queries set LegId and PositionId when the parent is known. Strategy queries set StrategyId, account ids, and UnderlyingContractId/Underlying. Underlying queries set UnderlyingContractId/Underlying only. Underlying is a denormalized display label; UnderlyingContractId is the stable key.

Field	Type	Required	Nullable	Default	Description
PositionId	int	No	Yes		Live position id when the series is position-scoped, or leg-scoped with a known parent position.
LegId	int	No	Yes		Live leg id when the series is leg-scoped.
StrategyId	int	No	Yes		Live strategy id when the series is strategy-scoped.
UnderlyingContractId	int	No	Yes		Underlying live contract id when the series is strategy-scoped or underlying-scoped.
Underlying	str	No	Yes		Denormalized underlying display label stored by the source row, when present.
LiveAccountId	int	No	Yes		Internal live account id when the series is account-scoped.
BrokerAccountId	str	No	Yes		Provider-specific broker account id when available.
BrokerType	BrokerType	No	Yes		Broker/provider backing the account when available.