Universe settings and security initializers enable you to configure some properties of the securities in a universe.


The universe settings of your algorithm configure some properties of the universe constituents. The following table describes the properties of the UniverseSettings object:

PropertyData TypeDescriptionDefault Value
ExtendedMarketHoursboolShould assets also feed extended market hours? You only receive extended market hours data if you create the subscription with an intraday resolution. If you create the subscription with daily resolution, the daily bars only reflect the regular trading hours.falseFalse
FillForwardboolShould asset data fill forward?trueTrue
MinimumTimeInUniverseTimeSpantimedeltaWhat's the minimum time assets should be in the universe?TimeSpan.FromDays(1)timedelta(1)
ResolutionResolutionWhat resolution should assets use?Resolution.Minute
ContractDepthOffsetintWhat offset from the current front month should be used for continuous Future contracts? 0 uses the front month and 1 uses the back month contract. This setting is only available for Future assets.0
DataMappingModeDataMappingModeHow should continuous Future contracts be mapped? This setting is only available for Future assets.DataMappingMode.OpenInterest
DataNormalizationModeDataNormalizationModeHow should historical prices be adjusted? This setting is only available for Equity and Futures assets.DataNormalizationMode.Adjusted
LeveragedecimalfloatWhat leverage should assets use in the universe? This setting is not available for derivative assets.Security.NullLeverage

To set the UniverseSettings, update the preceding properties in the Initialize method before you add the universe. These settings are globals, so they apply to all universes you create.

// Request second resolution data. This will be slow!
UniverseSettings.Resolution = Resolution.Second;
# Request second resolution data. This will be slow!
self.UniverseSettings.Resolution = Resolution.Second

Configure Universe Securities

Instead of configuring global universe settings, you can individually configure the settings of each security in the universe with a security initializer. Security initializers let you apply any security-level reality model or special data requests on a per-security basis. To set the security initializer, in the Initialize method, call the SetSecurityInitializer method and then define the security initializer.

//In Initialize

private void CustomSecurityInitializer(Security security)
    // Disable trading fees
    security.SetFeeModel(new ConstantFeeModel(0, "USD"));
#In Initialize

def CustomSecurityInitializer(self, security: Security) -> None:
    # Disable trading fees
    security.SetFeeModel(ConstantFeeModel(0, "USD"))

For simple requests, you can use the functional implementation of the security initializer. This style lets you configure the security object with one line of code.

SetSecurityInitializer(security => security.SetFeeModel(new ConstantFeeModel(0, "USD")));
self.SetSecurityInitializer(lambda security: security.SetFeeModel(ConstantFeeModel(0, "USD")))

In some cases, you may want to trade a security in the same time loop that you create the security subscription. To avoid errors, use a security initializer to set the market price of each security to the last known price.

var seeder = new FuncSecuritySeeder(GetLastKnownPrices);
SetSecurityInitializer(security => seeder.SeedSecurity(security));
seeder = FuncSecuritySeeder(self.GetLastKnownPrices)
self.SetSecurityInitializer(lambda security: seeder.SeedSecurity(security))

If you call the SetSecurityInitializer method, it overwrites the default security initializer. The default security initializer uses the security-level reality models of the brokerage model to set the following reality models of each security:

The default security initializer also sets the leverage of each security and intializes each security with a seeder function. To extend upon the default security initializer instead of overwriting it, create a custom BrokerageModelSecurityInitializer.

// In Initialize
SetSecurityInitializer(new MySecurityInitializer(BrokerageModel, new FuncSecuritySeeder(GetLastKnownPrices)));

class MySecurityInitializer : BrokerageModelSecurityInitializer
    public MySecurityInitializer(IBrokerageModel brokerageModel, ISecuritySeeder securitySeeder)
        : base(brokerageModel, securitySeeder) {}
    public override void Initialize(Security security)
        // First, call the superclass definition
        // This method sets the reality models of each security using the default reality models of the brokerage model

        // Next, overwrite some of the reality models
        security.SetFeeModel(new ConstantFeeModel(0, "USD"));
# In Initialize
self.SetSecurityInitializer(MySecurityInitializer(self.BrokerageModel, FuncSecuritySeeder(self.GetLastKnownPrices)))

class MySecurityInitializer(BrokerageModelSecurityInitializer):

    def __init__(self, brokerage_model: IBrokerageModel, security_seeder: ISecuritySeeder) -> None:
        super().__init__(brokerage_model, security_seeder)

    def Initialize(self, security: Security) -> None:
        # First, call the superclass definition
        # This method sets the reality models of each security using the default reality models of the brokerage model

        # Next, overwrite some of the reality models
        security.SetFeeModel(ConstantFeeModel(0, "USD"))

Selection Frequency

Most universes run on a daily basis, but some can select assets at different frequencies.

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