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Interactive Brokers Trading Classes for Identifying Contracts

Article Quant Q&A · Author: Gascoyne
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Summary

The document describes the role of trading classes in Interactive Brokers contract identification. A trading class adds an identifying layer when a symbol, expiration, and currency may not uniquely distinguish securities, such as when related contracts have different multipliers. The class can be found through the broker’s symbol database.

For options on E-mini S&P futures, the document gives several class examples and explains that calls and puts associated with the same underlying can be grouped by option type. It also notes that a local symbol can identify a specific contract without requiring other contract fields such as expiration to be entered separately. The discussion is limited to contract identification in the IB API; it does not cover trading strategies, order execution, or the full set of class conventions across products.

Key ideas

  • A trading class helps disambiguate securities that share other contract attributes.
  • Contract multipliers may differ even when symbol, expiration, and currency are otherwise the same.
  • Interactive Brokers provides trading class information through its symbol database.
  • A local symbol can uniquely identify a specific contract and reduce the need to specify other fields.

Tags

FuturesOptionsMarket microstructure
Full text
# What exactly is a contract's "trading class"?


# What exactly is a contract's "trading class"?












Web searches for this are drowned in pages offering trading courses, and the InteractiveBrokers API doesn't expand at all on the term.

So what are contract trading classes, and what are some examples, in particular for e-minis?

## Answer by MonteCarloSims (score 3)

https://quant.stackexchange.com/a/44234

For IB's API, trading classes act as another layer for the unique identification of securities which otherwise might be ambiguous. On occasion something will trade with the same symbol, expiration, and currency, but hypothetically because of some corporate action it has a different multiplier.

They can be looked up in IB's symbol database.

List of E-Mini S&P (ES) futures options classes here. (Examples: E3C, ES, EW4, E1A, etc.)

If you want to be very specific, the LocalSymbol is a truly unique identifier and prevents other parameters such as expiration from needing to be entered into contract specification.

## Answer by AlRacoon (score 2)

https://quant.stackexchange.com/a/44227

For options, it is all of the same type of option for a particular underlying. For the e-minis, you are referring, all the calls where the underlying is e-minis is a class. Similarly for all the puts.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.