Index Options

Handling Data

Introduction

LEAN passes the data you request to the OnDataon_data method so you can make trading decisions. The default OnDataon_data method accepts a Slice object, but you can define additional OnDataon_data methods that accept different data types. For example, if you define an OnDataon_data method that accepts a TradeBar argument, it only receives TradeBar objects. The Slice object that the OnDataon_data method receives groups all the data together at a single moment in time. To access the Slice outside of the OnDataon_data method, use the CurrentSlicecurrent_slice property of your algorithm.

All the data formats use DataDictionary objects to group data by Symbol and provide easy access to information. The plural of the type denotes the collection of objects. For instance, the TradeBars DataDictionary is made up of TradeBar objects. To access individual data points in the dictionary, you can index the dictionary with the contract ticker or Symbolsymbol, but we recommend you use the Symbolsymbol.

To view the resolutions that are available for Index Options data, see Resolutions.

Trades

TradeBar objects are price bars that consolidate individual trades from the exchanges. They contain the open, high, low, close, and volume of trading activity over a period of time.

Tradebar decomposition

To get the TradeBar objects in the Slice, index the Slice or index the Barsbars property of the Slice with the contract Symbolsymbol. If the contract doesn't actively trade or you are in the same time step as when you added the contract subscription, the Slice may not contain data for your Symbolsymbol. To avoid issues, check if the Slice contains data for your contract before you index the Slice with the contract Symbolsymbol.

public override void OnData(Slice slice)
{
    // Check if the symbol is contained in TradeBars object
    if (slice.Bars.ContainsKey(_contractSymbol))
    {
        // Obtain the mapped TradeBar of the symbol
        var tradeBar = slice.Bars[_contractSymbol];
    }
}

def on_data(self, slice: Slice) -> None:
    # Obtain the mapped TradeBar of the symbol if any
    trade_bar = slice.bars.get(self._contract_symbol)   # None if not found

You can also iterate through the TradeBars dictionary. The keys of the dictionary are the Symbol objects and the values are the TradeBar objects.

public override void OnData(Slice slice)
{
    // Iterate all received Symbol-TradeBar key-value pairs
    foreach (var kvp in slice.Bars)
    {
        var symbol = kvp.Key;
        var tradeBar = kvp.Value;
        var closePrice = tradeBar.Close;
    }
}
def on_data(self, slice: Slice) -> None:
    # Iterate all received Symbol-TradeBar key-value pairs
    for symbol, trade_bar in slice.bars.items():
        close_price = trade_bar.close

TradeBar objects have the following properties:

Quotes

QuoteBar objects are bars that consolidate NBBO quotes from the exchanges. They contain the open, high, low, and close prices of the bid and ask. The Openopen, Highhigh, Lowlow, and Closeclose properties of the QuoteBar object are the mean of the respective bid and ask prices. If the bid or ask portion of the QuoteBar has no data, the Openopen, Highhigh, Lowlow, and Closeclose properties of the QuoteBar copy the values of either the Bidbid or Askask instead of taking their mean.

Quotebar decomposition

To get the QuoteBar objects in the Slice, index the QuoteBars property of the Slice with the contract Symbolsymbol. If the contract doesn't actively get quotes or you are in the same time step as when you added the contract subscription, the Slice may not contain data for your Symbolsymbol. To avoid issues, check if the Slice contains data for your contract before you index the Slice with the contract Symbolsymbol.

public override void OnData(Slice slice)
{
    // Check if the symbol is contained in QuoteBars object
    if (slice.QuoteBars.ContainsKey(_contractSymbol))
    {
        // Obtain the mapped QuoteBar of the symbol
        var quoteBar = slice.QuoteBars[_contractSymbol];
    }
}

def on_data(self, slice: Slice) -> None:
    # Obtain the mapped QuoteBar of the symbol if any
    quote_bar = slice.quote_bars.get(self._contract_symbol)   # None if not found

You can also iterate through the QuoteBars dictionary. The keys of the dictionary are the Symbol objects and the values are the QuoteBar objects.

public override void OnData(Slice slice)
{
    // Iterate all received Symbol-QuoteBar key-value pairs
    foreach (var kvp in slice.QuoteBars)
    {
        var symbol = kvp.Key;
        var quoteBar = kvp.Value;
        var askPrice = quoteBar.Ask.Close;
    }
}
def on_data(self, slice: Slice) -> None:
    # Iterate all received Symbol-QuoteBar key-value pairs
    for symbol, quote_bar in slice.quote_bars.items():
        ask_price = quote_bar.ask.close

QuoteBar objects let LEAN incorporate spread costs into your simulated trade fills to make backtest results more realistic.

QuoteBar objects have the following properties:

Option Chains

OptionChain objects represent an entire chain of Option contracts for a single underlying security.

To get the OptionChain, index the OptionChainsoption_chains property of the Slice with the canonical Symbol.

public override void OnData(Slice slice)
{
    // Try to get the OptionChain using the canonical symbol
    if (slice.OptionChains.TryGetValue(_contractSymbol.Canonical, out var chain))
    {
        // Get all contracts if the OptionChain contains any member
        var contracts = chain.Contracts;
    }
}
def on_data(self, slice: Slice) -> None:
    # Try to get the OptionChain using the canonical symbol (None if no OptionChain return)
    chain = slice.option_chains.get(self._contract_symbol.Canonical)
    if chain:
        # Get all contracts if the OptionChain contains any member
        contracts = chain.contracts

You can also loop through the OptionChainsoption_chains property to get each OptionChain.

public override void OnData(Slice slice)
{
    // Iterate all received Canonical Symbol-OptionChain key-value pairs
    foreach (var kvp in slice.OptionChains)
    {
        var canonicalSymbol = kvp.Key;
        var chain = kvp.Value;
        var contracts = chain.Contracts;
    }
}
def on_data(self, slice: Slice) -> None:
    # Iterate all received Canonical Symbol-OptionChain key-value pairs
    for canonical_symbol, chain in slice.option_chains.items():
        contracts = chain.contracts

OptionChain objects have the following properties:

Option Contracts

OptionContract objects represent the data of a single Option contract in the market. To get the Option contracts in the Slice, use the Contractscontracts property of the OptionChain. 

public override void OnData(Slice slice)
{
    // Try to get the OptionChain using the canonical symbol
    if (slice.OptionChains.TryGetValue(_contractSymbol.Canonical, out var chain))
    {
        // Get individual contract data
        if (chain.Contracts.TryGetValue(_contractSymbol, out var contract))
        {
            var price = contract.Price;
        }
    }
}
def on_data(self, slice: Slice) -> None:
    # Try to get the OptionChain using the canonical symbol
    chain = slice.option_chains.get(self._contract_symbol.canonical)
    if chain:
        # Get individual contract data
        contract = chain.contracts.get(self._contract_symbol)
        if contract:
            price = contract.price

Greeks and Implied Volatility

To get the Greeks and implied volatility of an Option contract, use the Greeksgreeks and implied_volatility members.

public override void OnData(Slice slice)
{
    // Try to get the OptionChain using the canonical symbol
    if (slice.OptionChains.TryGetValue(_contractSymbol.Canonical, out var chain))
    {
        // Get individual contract data
        if (chain.Contracts.TryGetValue(_contractSymbol, out var contract))
        {
            // Get greeks data of the selected contract
            var delta = contract.Greeks.Delta;
            var iv = contract.ImpliedVolatility;
        }
    }
}
def on_data(self, slice: Slice) -> None:
    # Try to get the OptionChain using the canonical symbol
    chain = slice.option_chains.get(self._contract_symbol.canonical)
    if chain:
        # Get individual contract data
        contract = chain.contracts.get(self._contract_symbol)
        if contract:
            # Get greeks data of the selected contract
            delta = contract.greeks.delta
            iv = contract.implied_volatility

LEAN only calculates Greeks and implied volatility when you request them because they are expensive operations. If you invoke the Greeksgreeks property, the Greeks aren't calculated. However, if you invoke the Greeks.Deltagreeks.delta, LEAN calculates the delta. To avoid unecessary computation in your algorithm, only request the Greeks and implied volatility when you need them. For more information about the Greeks and implied volatility, see Options Pricing.

Open Interest

Open interest is the number of outstanding contracts that haven't been settled. It provides a measure of investor interest and the market liquidity, so it's a popular metric to use for contract selection. Open interest is calculated once per day. To get the latest open interest value, use the OpenInterestopen_interest property of the Option or OptionContractoption_contract.

public override void OnData(Slice slice)
{
    // Try to get the OptionChains using the canonical symbol
    if (slice.OptionChains.TryGetValue(_contractSymbol.Canonical, out var chain))
    {
        // Get individual contract data
        if (chain.Contracts.TryGetValue(_contractSymbol, out var contract))
        {
            // Get the open interest of the selected contracts
            var openInterest = contract.OpenInterest;
        }
    }
}

public void OnData(OptionChains optionChains)
{
    // Try to get the OptionChains using the canonical symbol
    if (optionChains.TryGetValue(_contractSymbol.Canonical, out var chain))
    {
        // Get individual contract data
        if (chain.Contracts.TryGetValue(_contractSymbol, out var contract))
        {
            // Get the open interest of the selected contracts
            var openInterest = contract.OpenInterest;
        }
    }
}

def on_data(self, slice: Slice) -> None:
    # Try to get the option_chains using the canonical symbol
    chain = slice.option_chains.get(self._contract_symbol.canonical)
    if chain:
        # Get individual contract data
        contract = chain.contracts.get(self._contract_symbol)
        if contract:
            # Get the open interest of the selected contracts
            open_interest = contract.open_interest

Properties

OptionContract objects have the following properties:

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