Risk
The risk subpackage groups all risk specific components and tooling.
Included is a PositionSizer component which can be used by trading strategies to help with risk management through position sizing.
class RiskEngine
Bases: Component
RiskEngine(PortfolioFacade portfolio, MessageBus msgbus, Cache cache, Clock clock, config: RiskEngineConfig | None = None)
Provides a high-performance risk engine.
The RiskEngine is responsible for global strategy and portfolio risk within the platform. This includes both pre-trade risk checks and post-trade risk monitoring.
Possible trading states:
: - ACTIVE
(trading is enabled).
REDUCING
(only new orders or updates which reduce an open position are allowed).HALTED
(all trading commands except cancels are denied).
- Parameters:
- portfolio (PortfolioFacade) – The portfolio for the engine.
- msgbus (MessageBus) – The message bus for the engine.
- cache (Cache) – The cache for the engine.
- clock (Clock) – The clock for the engine.
- config (RiskEngineConfig , optional) – The configuration for the instance.
- Raises: TypeError – If config is not of type RiskEngineConfig.
command_count
The total count of commands received by the engine.
- Returns: int
debug
If debug mode is active (will provide extra debug logging).
- Returns: bool
degrade(self) → void
Degrade the component.
While executing on_degrade() any exception will be logged and reraised, then the component
will remain in a DEGRADING
state.
WARNING
Do not override.
If the component is not in a valid state from which to execute this method, then the component state will not change, and an error will be logged.
dispose(self) → void
Dispose of the component.
While executing on_dispose() any exception will be logged and reraised, then the component
will remain in a DISPOSING
state.
WARNING
Do not override.
If the component is not in a valid state from which to execute this method, then the component state will not change, and an error will be logged.
event_count
The total count of events received by the engine.
- Returns: int
execute(self, Command command) → void
Execute the given command.
- Parameters: command (Command) – The command to execute.
fault(self) → void
Fault the component.
Calling this method multiple times has the same effect as calling it once (it is idempotent). Once called, it cannot be reversed, and no other methods should be called on this instance.
While executing on_fault() any exception will be logged and reraised, then the component
will remain in a FAULTING
state.
WARNING
Do not override.
If the component is not in a valid state from which to execute this method, then the component state will not change, and an error will be logged.
classmethod fully_qualified_name(cls) → str
Return the fully qualified name for the components class.
- Return type: str
id
The components ID.
- Returns: ComponentId
is_bypassed
If the risk engine is completely bypassed.
- Returns: bool
is_degraded
bool
Return whether the current component state is DEGRADED
.
- Return type: bool
- Type: Component.is_degraded
is_disposed
bool
Return whether the current component state is DISPOSED
.
- Return type: bool
- Type: Component.is_disposed
is_faulted
bool
Return whether the current component state is FAULTED
.
- Return type: bool
- Type: Component.is_faulted
is_initialized
bool
Return whether the component has been initialized (component.state >= INITIALIZED
).
- Return type: bool
- Type: Component.is_initialized
is_running
bool
Return whether the current component state is RUNNING
.
- Return type: bool
- Type: Component.is_running
is_stopped
bool
Return whether the current component state is STOPPED
.
- Return type: bool
- Type: Component.is_stopped
max_notional_per_order(self, InstrumentId instrument_id)
Return the current maximum notional per order for the given instrument ID.
- Return type:
Decimal or
None
max_notionals_per_order(self) → dict
Return the current maximum notionals per order settings.
- Return type: dict[InstrumentId, Decimal]
max_order_modify_rate(self) → tuple
Return the current maximum order modify rate limit setting.
- Returns: The limit per timedelta interval.
- Return type: (int, timedelta)
max_order_submit_rate(self) → tuple
Return the current maximum order submit rate limit setting.
- Returns: The limit per timedelta interval.
- Return type: (int, timedelta)
process(self, Event event) → void
Process the given event.
- Parameters: event (Event) – The event to process.
reset(self) → void
Reset the component.
All stateful fields are reset to their initial value.
While executing on_reset() any exception will be logged and reraised, then the component
will remain in a RESETTING
state.
WARNING
Do not override.
If the component is not in a valid state from which to execute this method, then the component state will not change, and an error will be logged.
resume(self) → void
Resume the component.
While executing on_resume() any exception will be logged and reraised, then the component
will remain in a RESUMING
state.
WARNING
Do not override.
If the component is not in a valid state from which to execute this method, then the component state will not change, and an error will be logged.
set_max_notional_per_order(self, InstrumentId instrument_id, new_value) → void
Set the maximum notional value per order for the given instrument ID.
Passing a new_value of None
will disable the pre-trade risk max
notional check.
- Parameters:
- instrument_id (InstrumentId) – The instrument ID for the max notional.
- new_value (integer , float , string or Decimal) – The max notional value to set.
- Raises:
- decimal.InvalidOperation – If new_value not a valid input for decimal.Decimal.
- ValueError – If new_value is not
None
and not positive.
set_trading_state(self, TradingState state) → void
Set the trading state for the engine.
- Parameters: state (TradingState) – The state to set.
shutdown_system(self, unicode reason=None) → void
Initiate a system-wide shutdown by generating and publishing a ShutdownSystem command.
The command is handled by the system’s NautilusKernel, which will invoke either stop (synchronously) or stop_async (asynchronously) depending on the execution context and the presence of an active event loop.
- Parameters: reason (str , optional) – The reason for issuing the shutdown command.
start(self) → void
Start the component.
While executing on_start() any exception will be logged and reraised, then the component
will remain in a STARTING
state.
WARNING
Do not override.
If the component is not in a valid state from which to execute this method, then the component state will not change, and an error will be logged.
state
ComponentState
Return the components current state.
- Return type: ComponentState
- Type: Component.state
stop(self) → void
Stop the component.
While executing on_stop() any exception will be logged and reraised, then the component
will remain in a STOPPING
state.
WARNING
Do not override.
If the component is not in a valid state from which to execute this method, then the component state will not change, and an error will be logged.
trader_id
The trader ID associated with the component.
- Returns: TraderId
trading_state
The current trading state for the engine.
- Returns: TradingState
type
The components type.
- Returns: type
class FixedRiskSizer
Bases: PositionSizer
FixedRiskSizer(Instrument instrument)
Provides position sizing calculations based on a given risk.
- Parameters: instrument (Instrument) – The instrument for position sizing.
calculate(self, Price entry, Price stop_loss, Money equity, risk: Decimal, commission_rate: Decimal = Decimal(0), exchange_rate: Decimal = Decimal(1), hard_limit: Decimal | None = None, unit_batch_size: Decimal = Decimal(1), int units=1) → Quantity
Calculate the position size quantity.
- Parameters:
- entry (Price) – The entry price.
- stop_loss (Price) – The stop loss price.
- equity (Money) – The account equity.
- risk (Decimal) – The risk percentage.
- exchange_rate (Decimal) – The exchange rate for the instrument quote currency vs account currency.
- commission_rate (Decimal) – The commission rate (>= 0).
- hard_limit (Decimal , optional) – The hard limit for the total quantity (>= 0).
- unit_batch_size (Decimal) – The unit batch size (> 0).
- units (int) – The number of units to batch the position into (> 0).
- Raises:
- ValueError – If risk_bp is not positive (> 0).
- ValueError – If xrate is not positive (> 0).
- ValueError – If commission_rate is negative (< 0).
- ValueError – If hard_limit is not
None
and is not positive (> 0). - ValueError – If unit_batch_size is not positive (> 0).
- ValueError – If units is not positive (> 0).
- Return type: Quantity
instrument
The instrument for position sizing.
- Returns: Instrument
update_instrument(self, Instrument instrument) → void
Update the internal instrument with the given instrument.
- Parameters: instrument (Instrument) – The instrument for the update.
- Raises: ValueError – If instrument does not equal the currently held instrument.
class PositionSizer
Bases: object
PositionSizer(Instrument instrument)
The base class for all position sizers.
- Parameters: instrument (Instrument) – The instrument for position sizing.
WARNING
This class should not be used directly, but through a concrete subclass.
calculate(self, Price entry, Price stop_loss, Money equity, risk: Decimal, commission_rate: Decimal = Decimal(0), exchange_rate: Decimal = Decimal(1), hard_limit: Decimal | None = None, unit_batch_size: Decimal = Decimal(1), int units=1) → Quantity
Abstract method (implement in subclass).
instrument
The instrument for position sizing.
- Returns: Instrument
update_instrument(self, Instrument instrument) → void
Update the internal instrument with the given instrument.
- Parameters: instrument (Instrument) – The instrument for the update.
- Raises: ValueError – If instrument does not equal the currently held instrument.