Equity
Liquidity Universes
Selection Frequency
Equity universes run on a daily basis by default. To adjust the selection schedule, see Schedule.
Examples
The following examples demonstrate some common liquidity universes for US Equities.
Example 1: Minute-Resolution Universe
The following algorithm asynchronously selects the 10 most liquid US Equities as the universe. It uses minute resolution data to provide the most realistic results.
class MinuteLiquidUniverseAlgorithm(QCAlgorithm): def initialize(self) -> None: # Use asynchronous universe selection to speed up your algorithm. self.universe_settings.asynchronous = True # Use minute resolution data so orders fill at realistic prices. self.universe_settings.resolution = Resolution.MINUTE # Add a universe of the 10 most liquid US Equities. self.add_universe(self.universe.dollar_volume.top(10))
Example 2: Trade Liquid Assets off Bollinger Bands
The following algorithm asynchronously selects the 500 most liquid US Equities as the universe. Each day, it forms a portfolio of the assets in the universe that are below their lower Bollinger Band .
class AsynchronousLiquidUniverseAlgorithm(QCAlgorithm): def initialize(self) -> None: self.set_start_date(2024, 1, 1) self.set_end_date(2024, 7, 1) self.settings.automatic_indicator_warm_up = True # When a new asset enters the universe, seed its current price so you can trade it right away. self.set_security_initializer( BrokerageModelSecurityInitializer(self.brokerage_model, FuncSecuritySeeder(self.get_last_known_prices)) ) # Use asynchronous universe selection to speed up the algorithm. self.universe_settings.asynchronous = True # Use daily data. It doesn't affect accuracy since the trades fill at the daily market open. self.universe_settings.resolution = Resolution.DAILY # Add a universe of the 500 most liquid Equities. self._universe = self.add_universe(self.universe.dollar_volume.top(500)) def on_securities_changed(self, changes: SecurityChanges) -> None: # Create Bollinger Band indicators for the universe constituents. for security in changes.added_securities: security.bb = self.bb(security.symbol, 60, 2) # Deregister the indicators when assets leave the universe. for security in changes.removed_securities: self.deregister_indicator(security.bb) def on_data(self, slice: Slice) -> None: # Ensure there are TradeBar objects in the current slice. if not slice.bars: return # Select the Equities that are below their lower Bollinger Band. securities = [self.securities[symbol] for symbol in self._universe.selected] selected = [ security for security in securities if security.bb.is_ready and security.price and security.price < security.bb.lower_band.current.value ] # Form an equal-weighted portfolio with the selected assets. weight = 1 / len(selected) self.set_holdings([PortfolioTarget(security.symbol, weight) for security in selected], True)
Other Examples
For more examples, see the following algorithms: