Securities
Key Concepts
Introduction
A security is an individual financial asset that you can trade on an exchange.
LEAN models these unique assets with a Security
object, which the AddEquity
add_equity
, AddCrypto
add_crypto
, and similar methods return.
The Securities
securities
property of the QCAlgorithm
class is a dictionary where the keys are Symbol
objects and the values are Security
objects.
The Securities
securities
dictionary contains all of the securities that have been in the algorithm during its lifetime.
// Subscribe to the SPY. private Symbol _symbol; _symbol = AddEquity("SPY").symbol;
# Subscribe to the SPY. self._symbol = self.add_equity("SPY").symbol
Holdings
The holdings
Holdings
property of a Security
object contains information about the investment state and history of the security.
// Use the holdings object to get information on the asset position, such as the quantity and average price. var holdings = Securities[_symbol].Holdings; var quantity = holdings.Quantity;
# Use the holdings object to get information on the asset position, such as the quantity and average price. holdings = self.securities[self._symbol].holdings quantity = holdings.quantity
Alternatively, you can get the current holdings of a security with the Portfolio
portfolio
dictionary.
// Get the quantity of a security you hold through the Portfolio dictionary. var holdings = Portfolio[_symbol]; var quantity = holdings.Quantity;
# Get the quantity of a security you hold through the Portfolio dictionary. holdings = self.portfolio[self._symbol] quantity = holdings.quantity
Reality Models
Security
objects contain references to the security level reality models. To customize the behavior of each security, configure its reality models.
Tradable Status
The IsTradable
is_tradable
property shows whether you can trade a security. The property value is true when the security is in the universe, even if the data starts at a later day. Indices, canonical Option securities, and continuous Futures contracts are not tradable. In live mode, custom data objects are also not tradable, even if the custom data represents a tradable asset.
// Check if the security is tradable. var tradable = Securities[_symbol].IsTradable;
# Check if the security is tradable. tradable = self.securities[self._symbol].is_tradable
Symbol Properties
The SymbolProperties
symbol_properties
property of a Security
contains properties for that specific security, such as the lot size and the minimum price variation.
// Round orders to a brokerage's lot size and minimum price variation using the symbol_properties. var symbolProperties = Securities[_symbol].SymbolProperties; var lotSize = symbolProperties.LotSize; var minimumPriceVariation = symbolProperties.MinimumPriceVariation;
# Round orders to a brokerage's lot size and minimum price variation using the symbol_properties. symbol_properties = self.securities[self._symbol].symbol_properties lot_size = symbol_properties.lot_size minimum_price_variation = symbol_properties.minimum_price_variation
Market Hours
The Exchange
exchange
property of a Security
contains information about the exchange that lists the security.
For example, the Exchange.Hours
exchange.hours
property contains information on the trading days and hours.
// Using the exchange object, check if the exchange's regular trading hours are open at the given time. var exchange = Securities[_symbol].Exchange; var hours = exchange.Hours; var isOpenNow = hours.isOpen(Time, extendedMarketHours: false); var minimumPriceVariation = symbolProperties.MinimumPriceVariation;
# Using the exchange object, check if the exchange's regular trading hours are open at the given time. exchange = self.securities[self._symbol].exchange hours = exchange.hours is_open_now = hours.is_open(self.time, extended_market_hours=False)
Custom Security Properties
You can add propertiesattributes to the Security
object. For example, you can add an exponential moving average.
// Cast the Equity to a dynamic object to add an EMA indicator to it. dynamic equity = AddEquity("SPY"); equity.ema = EMA(equity.Symbol, 10, Resolution.Daily);
# Add an EMA indicator to the SPY Equity object. equity = self.add_equity("SPY") equity.ema = self.ema(equity.symbol, 10, Resolution.DAILY)
This feature is helpful because you can get the Security
object from the Securities
securities
object.
// Get the SPY Equity object from Securities to get the EMA indicator. var ema = (decimal)(Securities["SPY"] as dynamic).ema.Current.Value;
# Get the SPY Equity object from Securities to get the EMA indicator. ema = self.securities["SPY"].ema.current.value
To avoid casting to and from the dynamic
type, you can use the Get<T>
method to access the dynamic member and return the object with its type.
// Get the SPY Equity object from Securities to get the EMA indicator and its current value var ema = Securities["SPY"].Get<ExponentialMovingAverage>("ema"); // The type of ema is ExponentialMovingAverage var emaValue = ema.Current.Value; // The type of emaValue is decimal
If the type or the member name is incorrect, the Get<T>
method causes a runtime error.