Equity
Legacy Fundamental Universes
Introduction
Warning: This API for Universe Selection was deprecated on November 2023. Please refer to the new Fundamental Universe API.
There are several ways to create an Equities universe. You can select a universe based on CoarseFundamental
data
or the constituents of an ETF, and then you can further filter your universe down with corporate fundamentals.
The following sections explain each of these techniques in detail.
Coarse Universe Selection
A coarse universe enables you pick a set of stocks based on their trading volume, price, or whether they have fundamental data. To add a coarse universe, in the Initialize
initialize
method, pass a filter function to the AddUniverse
add_universe
method. The coarse filter function receives a list of CoarseFundamental
objects and must return a list of Symbol
objects. The Symbol
objects you return from the function are the constituents of the universe and LEAN automatically creates subscriptions for them. Don't call AddEquity
add_equity
in the filter function.
public class MyCoarseUniverseAlgorithm : QCAlgorithm { public override void Initialize() { UniverseSettings.Asynchronous = true; AddUniverse(CoarseFilterFunction); } private IEnumerable<Symbol> CoarseFilterFunction(IEnumerable<CoarseFundamental> coarse) { return (from c in coarse orderby c.DollarVolume descending select c.Symbol).Take(100); } }
class MyCoarseUniverseAlgorithm(QCAlgorithm): def initialize(self) -> None: self.universe_settings.asynchronous = True self.add_universe(self._coarse_filter_function) def _coarse_filter_function(self, coarse: List[CoarseFundamental]) -> List[Symbol]: sorted_by_dollar_volume = sorted(coarse, key=lambda x: x.dollar_volume, reverse=True) return [c.symbol for c in sorted_by_dollar_volume[:100]]
CoarseFundamental
objects have the following attributes:
The total number of stocks in the US Equity Security Master dataset is 30,000 but your coarse filter function won't receive all of these at one time because the US Equity Security Master dataset is free of survivorship bias and some of the securities have delisted over time. The number of securities that are passed into your coarse filter function depends on the date of your algorithm. Currently, there are about 10,000 securities that LEAN passes into your coarse filter function.
Fundamentals Selection
A fundamental universe lets you select stocks based on corporate fundamental data. This data is powered by Morningstar® and includes approximately 8,100 tickers with 900 properties each. Due to the sheer volume of information, fundamental selection is performed on the output of another universe filter. Think of this process as a 2-stage filter. An initial filter function selects a set of stocks and then a fine fundamental filter function selects a subset of those stocks.
To add a fundamental universe, in the Initialize
initialize
method, pass two filter functions to the AddUniverse
add_universe
method. The first filter function can be a coarse universe filter, dollar volume filter, or an ETF constituents filter. The second filter function receives a list of FineFundamental
objects and must return a list of Symbol
objects. The list of FineFundamental
objects contains a subset of the Symbol
objects that the first filter function returned. The Symbol
objects you return from the second function are the constituents of the fundamental universe and LEAN automatically creates subscriptions for them. Don't call AddEquity
add_equity
in the filter function.
Only 8,100 assets have fundamental data. If your first filter function receives CoarseFundamental
data, you should only select assets that have a true value for their HasFundamentalData
has_fundamental_data
property.
public class MyUniverseAlgorithm : QCAlgorithm { public override void Initialize() { UniverseSettings.Asynchronous = true; AddUniverse(CoarseFilterFunction, FineFundamentalFilterFunction); } // filter based on CoarseFundamental IEnumerable<Symbol> CoarseFilterFunction(IEnumerable<CoarseFundamental> coarse) { // In addition to further coarse universe selection, ensure the security has fundamental data return (from c in coarse where c.HasFundamentalData select c.Symbol); } // filter based on FineFundamental public IEnumerable<Symbol> FineFundamentalFilterFunction(IEnumerable<FineFundamental> fine) { // Return a list of Symbols } }
class MyUniverseAlgorithm(QCAlgorithm): def initialize(self) -> None: self.universe_settings.asynchronous = True self.add_universe(self._coarse_filter_function, self._fine_fundamental_function) def _coarse_filter_function(self, coarse: List[CoarseFundamental]) -> List[Symbol]: # In addition to further coarse universe selection, ensure the security has fundamental data return [c.symbol for c in coarse if c.has_fundamental_data] def _fine_fundamental_function(self, fine: List[FineFundamental]) -> List[Symbol]: # Return a list of Symbols
FineFundamental
objects have the following attributes:
Example
The simplest example of accessing the fundamental object would be harnessing the iconic PE ratio for a stock. This is a ratio of the price it commands to the earnings of a stock. The lower the PE ratio for a stock, the more affordable it appears.
// Take the top 50 by dollar volume using coarse // Then the top 10 by PERatio using fine UniverseSettings.Asynchronous = true; AddUniverse( coarse => { return (from c in coarse where c.Price > 10 && c.HasFundamentalData orderby c.DollarVolume descending select c.Symbol).Take(50); }, fine => { return (from f in fine orderby f.ValuationRatios.PERatio ascending select f.Symbol).Take(10); });
# In Initialize: self.universe_settings.asynchronous = True self.add_universe(self._coarse_selection_function, self._fine_selection_function) def _coarse_selection_function(self, coarse: List[CoarseFundamental]) -> List[Symbol]: sorted_by_dollar_volume = sorted(coarse, key=lambda x: x.dollar_volume, reverse=True) filtered = [x.symbol for x in sorted_by_dollar_volume if x.has_fundamental_data] return filtered[:50] def _fine_selection_function(self, fine: List[FineFundamental]) -> List[Symbol]: sorted_by_pe_ratio = sorted(fine, key=lambda x: x.valuation_ratios.pe_ratio, reverse=False) return [x.symbol for x in sorted_by_pe_ratio[:10]]
Asset Categories
In addition to valuation ratios, the US Fundamental Data from Morningstar has many other data point attributes, including over 200 different categorization fields for each US stock. Morningstar groups these fields into sectors, industry groups, and industries.
Sectors are large super categories of data. To get the sector of a stock, use the MorningstarSectorCode
property.
var tech = fine.Where(x => x.AssetClassification.MorningstarSectorCode == MorningstarSectorCode.Technology);
tech = [x for x in fine if x.asset_classification.morningstar_sector_code == MorningstarSectorCode.TECHNOLOGY]
Industry groups are clusters of related industries that tie together. To get the industry group of a stock, use the MorningstarIndustryGroupCode
property.
var ag = fine.Where(x => x.AssetClassification.MorningstarIndustryGroupCode == MorningstarIndustryGroupCode.Agriculture);
ag = [x for x in fine if x.asset_classification.morningstar_industry_group_code == MorningstarIndustryGroupCode.AGRICULTURE]
Industries are the finest level of classification available. They are the individual industries according to the Morningstar classification system. To get the industry of a stock, use the MorningstarIndustryCode
.
var coal = fine.Where(x => x.AssetClassification.MorningstarIndustryCode == MorningstarSectorCode.Coal);
coal = [x for x in fine if x.asset_classification.morningstar_industry_code == MorningstarSectorCode.COAL]
Practical Limitations
Like coarse universes, fine universes allow you to select an unlimited universe of assets to analyze. Each asset in the universe consumes approximately 5MB of RAM, so you may quickly run out of memory if your universe filter selects many assets. If you backtest your algorithms in the Algorithm Lab, familiarize yourself with the RAM capacity of your backtesting and live trading nodes. To keep your algorithm fast and efficient, only subscribe to the assets you need.
Live Trading Considerations
The live data for fundamental universe selection arrives at 6/7 AM Eastern Time (ET), so fundamental universe selection runs for live algorithms between 7 and 8 AM ET. This timing allows you to place trades before the market opens. Don't schedule anything for midnight because the universe selection data isn't ready yet.
Examples
The legacy fundamental universe is deprecated. For examples of the new fundamental universe API, see Examples.