Options mechanics
Open Interest
The number of outstanding option contracts that remain open.
What Open Interest Means
Open interest counts contracts not yet closed, exercised, assigned, or expired. It is generally reported by option series on a delayed basis.
How to Read the Result
A new long matched with a new short can add 1 to open interest; closing an existing pair can subtract 1.
Limitations
- It is not daily volume.
- It does not guarantee a tight spread.
- Reported values may lag trading.
Common Questions
Can volume exceed open interest?
Yes. Contracts can change hands multiple times during one session.