What Is the OCC Option Symbol Format?
A developer-oriented answer for parsing OCC and OSI-style option symbols.
The practical OCC option symbol format is root symbol, expiration date in YYMMDD format, C or P for call or put, then an eight-digit strike stored in thousandths. Example: SPY 260515C00500000 means SPY, May 15 2026, call, 500.00 strike.
Root
1-6 chars
Can be padded with spaces in fixed-width displays.
Expiration
YYMMDD
Six digits after the root.
Strike
8 digits
Stored in thousandths, so 00500000 means 500.000.
Parser order
A parser should split the symbol into root, expiration, option type, and strike. The root can be compact or padded, so do not assume every visible character belongs to the date.
After parsing, normalize the expiration into ISO date format and divide the strike integer by 1,000. That gives a stable internal representation for API calls and UI labels.
OCC symbol fields
API example
Verify the answer with listed data
contract lookup
curl "https://api.cutemarkets.com/v1/options/contracts/O:SPY260515C00500000/" \
-H "Authorization: Bearer YOUR_API_KEY"How to implement
Implementation checklist
Read the root
Capture the root before the six-digit expiration block, allowing optional space padding.
Parse the expiration
Convert YYMMDD into an ISO date.
Parse type and strike
Read C or P, then divide the eight-digit strike by 1,000.
Last verified
This Q&A page was last reviewed on April 28, 2026. Date-sensitive market calendars, provider docs, and listed contracts can change, so production workflows should verify the live source before trading or publishing an automated answer.
Related questions
What does C mean in an OCC symbol?
C means call. P means put.
Why is the strike eight digits?
The strike is encoded in thousandths so fixed-width symbols can represent decimals.
Should I preserve spaces in the root?
Handle optional root padding while normalizing to the compact root used by your API or database.
Related pages
Options Q&A hub
Browse exact-answer pages for expirations, OCC symbols, options data, and provider comparisons.
OCC decoder
Decode option symbols interactively before wiring the parser into your workflow.
OCC option symbol guide
Read the full CuteMarkets guide to OCC and OSI symbol parsing.
Contracts docs
Fetch a single contract by OCC ticker or scan contracts by expiration.