What It Means
An option chain is the table every broker and exchange shows listing all available strike prices for an underlying's options, side by side with each strike's open interest, last traded price, and implied volatility for both calls and puts.
How It Works
Calls sit on one side of the table and puts on the other, both organized around the same column of strike prices running down the middle. The at-the-money (ATM) strike, the one closest to the current market price, is usually highlighted so you can see at a glance which strikes are in-the-money and which are out-of-the-money.
Reading across a single row tells you how one strike is priced and positioned on both the call and put side. Reading down a column tells you how OI or price is distributed across strikes, which is the raw data behind a lot of derived readings like Put Call Ratio.
Example
Pull up the Nifty option chain for the weekly expiry and you'll see rows for every strike from deep in-the-money to deep out-of-the-money, each showing OI, volume, and premium for both the call and the put at that strike, updating live through the session.
Related Terms
- F&O (Futures & Options) — the contract category shown in an option chain