What Is Open Interest in F&O?
Open interest shows how many derivative contracts are live. Combined with price, it hints at the strength of a move.
On this page
Open interest (OI) is the total number of outstanding (not yet closed or expired) futures or options contracts at a given time. It’s a measure of how much money is committed to a contract — distinct from volume.
Open interest vs volume
- Volume = how many contracts traded during the period (resets daily).
- Open interest = how many contracts remain open right now (carries over).
A new buyer and seller creating a fresh position increases OI; when existing holders close out, OI falls.
Reading price + OI together
Combining price direction with OI change is a classic technique:
- Price up + OI up → new buying, trend likely strong (long buildup).
- Price down + OI up → new selling (short buildup).
- Price up + OI down → short covering (shorts exiting), move may be less durable.
- Price down + OI down → long unwinding (longs exiting).
OI around expiry and rollover
Near expiry, traders move positions to the next series — a rollover. High rollover with rising OI suggests conviction in the ongoing trend.
The caveat
OI shows participation and commitment, not guaranteed direction — it’s a confirmation tool, best used with price action and the option chain, never alone. Derivatives are high-risk. Education only, not advice.
