An option chain is the list of every strike available for one underlying and one expiry, with calls on one side and puts on the other. It is the starting point for almost every options decision, from finding a contract to checking how liquid it is. NSE publishes one for each index and F&O stock, and most broker apps show their own version with similar columns.
The layout
- Strike prices run down the middle column.
- Calls (CE) are on the left, puts (PE) on the right, with the same set of columns mirrored on each side.
- At the top you choose the underlying (for example Nifty 50) and the expiry date, and the page shows the underlying's value at the time the data was taken.
- The data is a snapshot that refreshes; it is not tick-by-tick.
The columns, one by one
| Column | What it means | Why it matters |
|---|---|---|
| OI | Open interest: the number of contracts outstanding at that strike | How much money is committed there; see our open interest guide |
| Chng in OI | Change in open interest since the previous day | Whether positions are being opened or closed today |
| Volume | Contracts traded today | How active the strike is now; a strike can have high OI but little volume |
| IV | Implied volatility of that option, in percent | How expensive the option is in volatility terms |
| LTP | Last traded price (premium per unit) | The most recent trade; it can be stale in illiquid strikes |
| Chng | Change in LTP from the previous close | How much the premium has moved today |
| Bid Qty / Bid | Best price and quantity buyers are offering now | What you would get if you sold at market |
| Ask / Ask Qty | Best price and quantity sellers are asking now | What you would pay if you bought at market |
Quantities and OI on NSE are shown in contracts or units depending on the view; check the note on the page, because one contract is a whole lot.
The shaded strikes: in the money
NSE shades the in-the-money options. For calls that is every strike below the current index level; for puts every strike above it. So on the call side the shading covers the top part of the chain, on the put side the bottom part. The strike nearest the index level is at the money. Our moneyness guide explains the terms.
Reading one row
Say Nifty is "at 25,000" and you look at the 25,000 row of the weekly expiry. A made-up example of what you might see on the call side: OI 60,000 contracts, change in OI +8,000, volume 4,50,000, IV 14.0, LTP ₹209.21, bid ₹208.96, ask ₹209.46. All values are illustrative.
- The bid-ask spread is ₹0.50 per unit, a cost you pay whenever you trade at market. On a lot of 65 that is ₹32.50 between buying and selling immediately.
- Volume far above OI is normal for near-expiry at-the-money strikes: the same contracts change hands many times a day.
- Change in OI is positive, so more contracts were opened than closed today. On its own it does not tell you whether buyers or sellers initiated them.
Liquidity first
Before anything else, the chain shows where you can trade at a fair price. Near-the-money strikes of the nearest Nifty expiry are usually very liquid, with tight spreads and deep quantities. Far strikes, later expiries and many stock options can have wide spreads, small quantities and an LTP that is hours old. A wide spread means you lose money the moment you enter.
The LTP is not always the price
In illiquid strikes the last trade may have happened long ago. Always look at the current bid and ask, and prefer limit orders to market orders in options.
What people derive from the chain
- Put-call ratio (PCR): total put OI divided by total call OI.
- Max pain: the strike at which option buyers as a whole would receive the least at expiry.
- Strikes with the largest OI, which some traders read as support or resistance.
- The volatility skew: how IV changes across strikes.
Each of these has its own guide here. All of them describe the current positioning of the market; none of them reliably predicts where the index will go.
Examples use illustrative values, not current market data. This is general education, not investment advice.