OCC Option Symbol Structure and Whitespace Padding

Summary

The document describes the OCC-style 21-character format for exchange-traded option symbols. It breaks the descriptor into a seven-character root, a six-digit expiration date, a one-character call or put marker, and an eight-character strike field. It explains that shorter underlying symbols are padded with spaces in the root field and gives an example using an AAPL call, its expiration, and its strike. This fixed-width structure matters when systems parse and exchange option identifiers.

The author points out a potential integration issue: removing spaces may produce a shorter string that no longer follows the stated schema, while parsing from the right is proposed as a possible workaround. The document asks what formats are currently used in industry feeds, back ends, and integrations, but supplies no current standards or broker-specific answers. Its format description is presented as background rather than verified current guidance, so implementations should confirm the applicable feed specification and any vendor-specific conventions before relying on it.

Key ideas

• The described OCC option symbol uses fixed-width fields for root, expiration, option type, and strike.
• The root field is padded with spaces when the underlying symbol is shorter than its allotted width.
• Removing padding can create a string that does not conform to the stated fixed-width format.
• The document raises parsing and integration concerns but gives no current industry-wide or broker-specific answer.

Tags

# Whitespace in Option Symbols


# Whitespace in Option Symbols












A while ago exchange-traded option symbols migrated to a 21-character descriptor, formalized by the Options Clearing Corporation (OCC), consisting of:

- 7 characters: root or underlying symbol

- 6 characters: expiration date formatted YYMMDD

- 1 character : option type, C (call) or P (put)

- 8 characters: strike price, 5 for integer and 3 for fraction

Total length is 21 characters. For example, `AAPL 210116C00130000` stands for AAPL Call Option at $130.00 Expiring on 16-Jan-2021.

The symbol part must be padded with spaces if the underlying is shorter than 7 characters, and that must have created parsing and processing problems for tooling, API etc. One can arguably discard the spaces and decode the option symbol in reverse order interpreting any characters leading to date as the symbol, but `AAPL210116C00130000` would not be compliant with the proposed schema.

I could not locate up-to-date documents on the OCC site regarding option naming. What descriptors are currently used in the industry in data feeds, the back-end, and integrations?

References to option symbol changes at various US brokers:

- Interactive Brokers

- Schwab

- Fidelity

- Nasdaq

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.