🧾 Reading an NSE option chain, column by column

🎯 In 30 seconds: The option chain is the menu: for one underlying and one expiry, it lists every strike with its calls on the left and puts on the right. For each option you see open interest (OI), change in OI, volume, implied volatility (IV), last traded price (LTP), and the best bid and ask with their quantities. The most useful columns for a beginner are the bid, the ask and the gap between them, because that gap is a cost you pay on every trade. OI, the put-call ratio and "max pain" are widely watched on Indian trading screens, but there is little solid evidence that they predict where the Nifty goes.

What the chain is

Think of a sabzi mandi early in the morning. Every stall shows a price for the same tomatoes, and you can see who is shouting the lowest price to sell and who is offering the most to buy. The option chain is that view for options: one row for each strike, with the buy and sell prices on offer right now.

You will find it on NSE's website (Market Data, then Option Chain) and in every broker app. Pick the underlying (Nifty 50, Nifty Bank, or a stock that has options), then pick the expiry. The page shows the current value of the underlying at the top and the time of the snapshot. NSE's page can lag the live market by a little, so for an actual order always check the price in your broker's order window.

The layout is the same everywhere: strike prices run down the middle, calls are on the left and puts are on the right. The strike nearest the current price is the at-the-money (ATM) strike. Many screens shade the in-the-money (ITM) options: calls with strikes below the price and puts with strikes above it.

Choosing an expiry

The expiry dropdown is the first thing to set. What you will see, as of October 2026:

• Nifty 50: weekly expiries every Tuesday, monthly expiries on the last Tuesday of the month, plus quarterly and half-yearly contracts. NSE's contract page lists 4 weekly, 3 monthly, 3 quarterly and 8 half-yearly expiries, so some Nifty options run about five years out.
• Other NSE indices (Nifty Bank, Nifty Financial Services, Nifty Midcap Select, Nifty Next 50) and all stock options: monthly only, expiring on the last Tuesday of the month, under SEBI's May 2025 expiry rules.
• BSE: Sensex has weekly options expiring on Thursdays. BSE's other equity derivatives expire on the last Thursday of the month.

Almost all trading happens in the nearest expiry. SEBI's August 2026 study found that 59% of index option turnover in FY26 happened on the expiry day itself, and 97% within a week of expiry. Far expiries can show stale prices and wide gaps between bid and ask.

Strikes are spaced at fixed intervals. For Nifty 50 weekly and monthly options, NSE's contract page sets the interval at 50 points, with 35 strikes in the money, 1 at the money and 35 out of the money. Longer-dated Nifty contracts use wider intervals. Stock option strike intervals depend on the share price and are set by the exchange.

A sample chain, column by column

Hypothetical snapshot. Nifty 50 at 24,040, weekly expiry six days away. Prices in points; OI and change in OI in thousands of contracts. Real chains show more columns (volume, LTP change, bid and ask quantities) and many more strikes.

Column by column:

• OI (open interest): the number of contracts still open at that strike: positions that have been opened and not yet closed. Every open contract has a buyer and a seller, so OI says how much money is committed, not which side is "right". Check whether your screen shows OI in contracts or in units (contracts x lot size); apps differ.
• Chg OI (change in OI): how much OI rose or fell compared with the previous day's close. A rise means new positions were opened. A fall means positions were closed.
• Volume: the number of contracts traded today. High volume with little change in OI means traders are passing existing positions back and forth, which is common on expiry day.
• IV (implied volatility): the volatility, in percent per year, that makes a pricing model match the option's price. It is the market's price for expected movement, covered in Implied volatility and India VIX. In the sample, lower strikes carry higher IV. That pattern, called skew, is normal for index options because traders pay more for crash protection.
• LTP (last traded price) and change: the price of the most recent trade and how far it is from the previous close. In a thin option, the last trade might have been an hour ago and tells you little about the price now.
• Bid and bid quantity: the highest price someone is willing to pay right now, and for how much. If you sell at market, you get roughly the bid.
• Ask and ask quantity: the lowest price someone is willing to sell at right now, and for how much. If you buy at market, you pay roughly the ask.

Prices move in steps of ₹0.05 for Nifty options (NSE contract page), so the narrowest possible gap between bid and ask is 0.05 points.

Reading the sample chain like a trader

A few things a careful reader would notice in the snapshot above:

• The ATM strike is 24,000. It has the tightest bid-ask gaps on both sides and some of the highest OI. This is usually where the market is most liquid.
• Large call OI at 24,200 and 24,300. Many people read heavy call OI above the market as "resistance", on the idea that call sellers there will defend the level. Large put OI below the market (here at 23,800) is read as "support". Treat that as a story people tell, not a rule. OI shows where positions are, not what the market will do.
• Wide spreads on in-the-money options. The 24,300 put shows 308.00 / 312.50, a gap of 4.50 points or about ₹292 per lot. ITM options trade less, so their spreads are wider.
• The put side is busier below the market and the call side above it. Out-of-the-money options are cheaper and attract more trading, both from buyers looking for a cheap bet and sellers collecting premium.

OI and price together: the popular reading

Trading screens and social media often combine price change and OI change into four labels for futures and options. Here is the common reading, with the honest caveat after it.

The right-hand column is all the data truly tells you. Every new contract has both a buyer and a seller, so "long build-up" is equally a build-up of shorts. The labels guess which side was more eager. They can be useful for describing what happened today. They are much weaker as a guide to tomorrow.

The put-call ratio and max pain: popular, weakly supported

Put-call ratio (PCR) is total put OI divided by total call OI for an expiry. In the sample's six strikes it is (66 + 48 + 58 + 20 + 11 + 6) / (14 + 22 + 61 + 48 + 70 + 55) = 209 / 270 = 0.77. Some traders read a high PCR as "too many people hedged, the market will rise" and a low PCR as the reverse. Others read it the opposite way. That disagreement is itself a warning.

Max pain is the strike at which option buyers as a group would lose the most at expiry. The theory says the index tends to settle near it. It is quoted on many Indian sites, but this course found no NSE or SEBI evidence that it predicts the settlement level, and no solid published study of it on Indian data.

Spreads and liquidity: the hidden cost

The gap between bid and ask is a cost you pay every time you trade. If you buy at the ask and immediately sell at the bid, you lose the gap. On a liquid Nifty ATM option it may be 0.05 to 0.25 points, which is ₹3 to ₹16 per lot. On a thin stock option it can be several rupees per share on a lot of hundreds or thousands of shares.

Hypothetical stock option: Sharma Foods 1,550 call, monthly, bid ₹18.00, ask ₹21.50, lot 1,000 (hypothetical). The gap is ₹3.50 a share, which is ₹3,500 per lot. If you buy at ₹21.50, the option must rise to ₹21.50 at the bid just for you to break even on the spread, before brokerage, STT and other charges. That is a 19% hurdle on a ₹18 option.

Stock options in India are much less liquid than Nifty options. SEBI's FY26 study notes stock option turnover fell 10% that year while index options grew. The practical result: many strikes in many stocks have wide spreads and almost no trading.

A liquidity checklist

• Spread as a share of the price: under 1% is comfortable, above 5% is expensive. Divide (ask - bid) by the midpoint.
• Quantity at the bid and ask: enough to fill your order without moving the price.
• Volume today: regular trading through the day, not one trade at 10 am.
• OI: a healthy number of open contracts means there will likely be someone on the other side when you want to get out.
• LTP close to the bid-ask midpoint: if the LTP is far outside the current bid and ask, it is stale.

Use limit orders for options. A market order in a thin option can fill at a terrible price. Brokers apply market protection limits on market orders, but a limit order puts the price in your hands. Order types in depth covers the choices.

Other things on the screen

• Underlying value and time stamp: confirm the chain is current and which price it is centred on.
• Greeks: NSE's chain does not show delta, gamma, theta or vega. Many broker apps add them in an "option chain" or "strategy" view. The Greeks explains them.
• Total OI and PCR at the bottom: totals for the whole expiry. See the caution above.
• Quantity freeze: the largest order NSE accepts in one go for that contract. It is published by the exchange and matters only for large orders.
• Stock option chains: remember that ITM stock options held to expiry end in delivery, and that some stocks enter an F&O ban when OI crosses the market-wide limit, during which new positions are not allowed. See The rules every Indian trader runs into.

Try it

Open NSE's option chain for the Nifty 50 and pick the nearest expiry. In a notebook, for the ATM strike and for strikes 200 and 500 points away on each side, write down: OI, volume, LTP, bid, ask, and spread as a percentage of the midpoint. Then do the same for one stock you know on its monthly expiry. Compare the spreads. Which options would cost you more than 2% just to get in and out? Finally, compute the PCR for the whole Nifty expiry from the totals row, note it, and check after expiry whether it told you anything useful.

Sources

• NSE: Option chain
• NSE: Nifty 50 futures and options, contract specifications (trading cycle, strike intervals, price step)
• SEBI: Final settlement day (expiry day) for equity derivatives contracts, 26 May 2025 (PDF)
• Business Standard: NSE bids adieu to Thursday expiry as dates swap come into effect (August 2025)
• SEBI: Profitability of Individual Traders in the Equity Derivatives Segment (FY25 to FY26), August 2026 (PDF)