Guide · Options
How to read an option chain in India
The short answer
An option chain is a mirror table: strikes run down the centre, calls on the left and puts on the right, and for each strike both sides show the premium, the bid-ask spread, the volume, the implied volatility and the open interest. The strike nearest the spot is at-the-money. Reading it well is mostly telling apart two numbers that look alike: volume is today's flow and resets, while open interest is the standing stock of open positions. And the honest limit most guides skip: open interest tells you how much is committed at a strike, never the direction of what is committed there.
The option chain is the most information-dense screen a retail trader in India will ever look at, and it is free: the NSE publishes it in near-real time, no login required. That density is also the trap. Because every column carries a real quantity, it is tempting to read meaning into all of them at once, and most beginner mistakes come from reading a descriptive number as a predictive one. This guide takes the chain column by column, then spends its length on the one idea that separates a useful reading from a superstition: what open interest can suggest, and the far larger set of things it cannot tell you.
The layout: calls left, puts right, strikes down the spine
The chain is built around the strike ladder in the centre, running from low strikes at the top to high strikes at the bottom. To its left is everything about the call at each strike; to its right, everything about the put. The two sides are a mirror, so a single horizontal row lets you compare the call and the put that share a strike, and a single vertical column lets you see how one quantity, say open interest, changes as you walk up or down the strikes.
The anchor is the at-the-money (ATM) strike, the one closest to the current spot level of the underlying. Above the ATM, calls are out-of-the-money and puts are in-the-money; below it, the reverse. Most chains shade the in-the-money side, so the boundary between light and dark cells is the spot, and you can find the ATM at a glance without reading a single number.
Every column, by what it actually measures
Five quantities do the work on each side of the chain, and each answers a different question. Confusing them is the root of most misreadings, so it is worth stating precisely what each one is and, just as important, what it is not.
The premium (LTP) is the last traded price of that specific option, quoted per unit; your actual outlay is that figure times the lot size. Bid and ask are the best resting buy and sell prices, and the gap between them, the spread, is the immediate cost of transacting: a wide spread means you lose ground the instant you enter. Volume is the count of contracts traded so far today, a measure of activity that resets at the next open. Implied volatility (IV) is the volatility the market is pricing into that option, backed out of its premium; higher IV means a richer premium for the same strike and expiry. And open interest (OI) is the number of contracts currently outstanding at that strike, with change in OI showing how that stock moved during the session.
| Column | What it is | What it tells you | The caveat |
|---|---|---|---|
| Premium (LTP) | Last traded price of the option, per unit | The current cost of that contract | Times the lot size, and it can decay fast near expiry even if the underlying is still |
| Bid / Ask | Best buy and best sell price | The spread is your immediate cost to transact | Wide on illiquid strikes; the LTP is not the price you will actually get |
| Volume | Contracts traded today | Activity and liquidity for the session | Resets daily; high volume does not mean new positions were opened |
| Implied volatility | Volatility priced into the option | How rich the premium is for that strike | Describes cost, not direction; differs strike to strike |
| Open interest | Contracts currently outstanding | How much is committed at that strike | Silent on the direction, purpose or owner of those positions |
The subtle line in that table is between volume and open interest, because they are the two most cited numbers and the two most often conflated. They are not the same kind of thing at all: one is a flow, the other a level.
Volume is flow, open interest is stock
Think of the strike as a reservoir. Volume is the water that flowed through the pipe today, and it is reset to zero every morning. Open interest is the level actually standing in the reservoir, and it carries from one day to the next. Open interest rises only when a genuinely new contract is created, a fresh buyer meeting a fresh seller, and falls only when an existing position is closed. If two traders simply pass an existing contract between them, volume ticks up but open interest does not move at all. That is why volume can far exceed open interest on a busy day, and why change in OI is often the more informative figure: it isolates the fresh positioning from the churn.
Reading open interest honestly
Here is where a chain guide has to choose between being useful and being popular. The popular reading is simple: a strike with heavy put open interest below the spot is called support, a strike with heavy call open interest above it is called resistance, and the put-call ratio is quoted as a sentiment gauge. The logic is not nonsense: large written positions do cluster at round strikes, and the writers of those options have an interest in the price staying away from them, which can create real friction at those levels.
But that reading omits the single most important fact about open interest, and it is the differentiator of this guide: open interest cannot tell you the direction of a position. Every open contract has a buyer and a seller, so the number counts pairs, not a net stance. A jump in open interest at a call strike is equally consistent with a bull buying the call, a bear writing it, a fund hedging its stock, or a trader legging into a spread. The figure is identical in all four cases. Open interest is a measure of how much is committed at a strike; it is silent on who is committed, on which side, and why.
That is why OI-based support and resistance is a weak heuristic, not a law. In a fast directional move the crowded strike offers no protection at all; price cuts through it, the writers who were meant to defend it are stopped out or hedged elsewhere, and the level that looked solid evaporates. The same caution applies to max pain, the strike at which the largest quantity of open options would expire worthless: it is popular, it shifts constantly as open interest changes, and its predictive record is contested rather than established. Treat these as descriptions of where positions currently sit, never as forecasts of where price must go.
| Open interest can suggest | Open interest cannot tell you |
|---|---|
| Where large positions are concentrated (crowded strikes) | Whether those positions are bullish, bearish, hedges or spread legs |
| That a level is watched and may see friction | That price will actually respect that level in a strong move |
| Rough sentiment via the put-call ratio | Whether the ratio reflects conviction or routine hedging |
| That fresh positions are forming, via change in OI | Who is on the other side of each new contract |
| Where liquidity is deepest to transact | The future, of any kind: it is a snapshot, not a signal |
The put-call ratio is a crude gauge, not a signal. The PCR divides put open interest, or volume, by the call figure. A high ratio is read as heavy put activity, a low one as heavy call activity. But it is a lagging summary of past positioning, it cannot separate a hedge from a bet, and a single large institutional trade can swing it. It is one rough input among many. Read as a standalone trigger, it misleads more often than it helps.
Change in open interest and price: the buildup matrix
The one genuinely analytical use of open interest is to read its change alongside the change in price over the same window. This pairing is where traders infer whether a move is backed by fresh commitment or is merely old positions unwinding. There are four combinations, and each carries a conventional label. The important word throughout is infer: these are reasonable readings of positioning, not certainties, because, as above, the same OI change can come from a hedge or a spread rather than a directional view.
| Price | Open interest | Conventional label | The inference (not a certainty) |
|---|---|---|---|
| Rising | Rising | Long buildup | New long positions entering; the up-move has fresh backing |
| Falling | Rising | Short buildup | New short positions entering; the down-move has fresh backing |
| Rising | Falling | Short covering | Existing shorts closing; the up-move may be an exit, not new demand |
| Falling | Falling | Long unwinding | Existing longs closing; the down-move may be an exit, not new supply |
Used carefully, the matrix answers a narrow question well: is this move being driven by people arriving or people leaving? That distinction matters, because a rally on short covering is a different animal from a rally on fresh buying, and it can fade the moment the trapped shorts are done. But the matrix is still an inference layered on a number that hides direction, and it is at its weakest exactly when it feels most confident, in the middle of a violent move, when hedging flow and forced exits muddy every reading.
India specifics: where the chain lives, and where liquidity sits
In India the option chain is a public utility. The NSE publishes it free on its website, updated in near-real time through the trading session, so there is no cost or subscription to see strike-wise open interest, change in OI, volume, implied volatility and the put-call ratio. Index options carry both weekly and monthly expiries, while single-stock options settle monthly. Worth knowing for currency, because it dates careless guides: the exchange rationalised weekly index expiries through late 2024, so the roster of what expires weekly is narrower than older articles assume. Always confirm the expiry you are reading before you read anything else.
Liquidity is not spread evenly across the chain. It concentrates near the at-the-money strike and in the nearest expiry, where the bid-ask spread is tightest and the depth is real. As you move to far out-of-the-money strikes or far-dated expiries, volume thins and the spread widens into a genuine cost: the LTP may look like a price, but there is no one there to trade it at that figure. This is also where the arithmetic of options turns against the impatient. A far out-of-the-money weekly option looks cheap because its probability of paying off is low, and its time value drains quickly as expiry nears even when the underlying barely moves. The chain shows you the price. It does not show you the timing risk you take on by paying it.
The scale of the losses is not a footnote. A SEBI study released in July 2025 found that over 91 percent of individual traders in the equity derivatives segment lost money in FY25, with aggregate net losses of about ₹1,05,603 crore after costs, up roughly 41 percent on the prior year. A large share of that loss sits in exactly the low-probability weekly options that look inexpensive on the chain. Reading the chain accurately is, before anything else, a way to understand what you are actually buying.
What the chain is, and what it is not
Read plainly, the option chain is a live inventory of prices, costs and positioning across every strike of an expiry. That is a great deal, and it is genuinely useful: it tells you what an option costs, how expensive its volatility is, how liquid it is to trade, and where the crowd has gathered. What it is not, at any column, is a forecast. The premium is a price, not a prediction. Implied volatility is a cost, not a direction. Open interest is a stock of commitments whose direction is hidden by construction. Even the buildup matrix, the most analytical thing on the screen, only tells you whether a move is arrival or exit, and only as an inference.
So the skill the chain rewards is not pattern-spotting on a data-dense screen; it is knowing the exact boundary of what each number can support, and refusing to read past it. That discipline, holding a claim to what the evidence actually shows and no further, is the same judgement that separates a durable trader from a busy one, and it is exactly what the method we teach is built around. The chain hands you the facts. Reading them without inventing a story is the entire game.
Common Questions
Frequently Asked Questions
How do you read an option chain?
+Read it as a mirror. Strikes run down the centre, calls sit on the left and puts on the right, and the strike nearest the spot price is at-the-money. For each strike, both sides show the premium (LTP), the bid-ask spread, the volume, the implied volatility and the open interest with its change for the session. Read across one strike row to compare calls and puts at the same level, and read down a column to see where premium, participation and cost concentrate.
What is the difference between volume and open interest in an option chain?
+Volume is today's flow: how many contracts changed hands during the current session, and it resets to zero at the next open. Open interest is the standing stock: how many contracts are currently outstanding, and it carries over day to day. Open interest rises only when a new position is created and falls only when one is closed, so a strike can show high volume but little change in open interest if traders opened and closed the same day.
Does high open interest at a strike predict where the market will go?
+No. High put open interest below the spot is often read as support and high call open interest above it as resistance, because large written positions cluster there. But open interest is descriptive, not predictive, and the level is a weak heuristic that breaks in a fast move. It shows where positions sit, not where price must go, and it cannot tell you the direction of those positions.
Why can open interest not tell you the direction of a trade?
+Every open contract has a buyer and a seller, so open interest counts pairs, not a net view. A rise in open interest at a call strike could be a bull buying, a bear writing, a hedge against stock, or one leg of a spread, and the number looks identical in every case. Open interest measures how much is committed at a strike. It is silent on who is on which side and why.
How do you read change in open interest with price?
+Pair the direction of price with the direction of open interest. Rising price with rising open interest suggests fresh long buildup; falling price with rising open interest suggests short buildup; rising price with falling open interest suggests short covering; falling price with falling open interest suggests long unwinding. These are inferences about positioning, not certainties, because the same numbers can arise from hedging or spreads rather than directional conviction.
What is the put-call ratio and how reliable is it?
+The put-call ratio (PCR) divides put open interest (or volume) by the call figure, as a crude sentiment gauge: a high ratio is read as heavy put activity and a low one as heavy call activity. It is a lagging summary of past positioning, it cannot separate hedging from speculation, and large institutional trades can distort it. Treat it as one rough input among many, not a signal on its own.
What does implied volatility on the chain tell you?
+Implied volatility is the volatility the market is currently pricing into that specific option, worked back from its premium. Higher implied volatility means a richer premium for the same strike and expiry, because the market expects a wider range of outcomes. It describes the cost of the option, not the direction of the underlying, and it tends to differ from strike to strike, which is why two options at the same expiry can carry very different implied volatilities.
Where do you find the NSE option chain, and which options are most liquid?
+NSE publishes the option chain free on its website, updated in near-real time during market hours, with weekly and monthly expiries for index options and monthly expiries for stock options. Liquidity concentrates near the at-the-money strike and in the nearest expiry, where bid-ask spreads are tightest. Far out-of-the-money strikes and far-dated expiries can be thin, showing low volume and wide spreads that add a hidden cost to every entry and exit.
Where the facts come from
Sources
- NSE option chain. The National Stock Exchange publishes the option chain free and public, showing strike-wise open interest, change in OI, volume, implied volatility, the put-call ratio and the last traded price for index and stock options, updated in near-real time during market hours. nseindia.com
- Open interest, and its distinction from volume. Standard derivatives references establish the mechanics of open interest as the stock of outstanding contracts that changes only when positions are created or closed, its difference from daily traded volume, and the price-and-OI interpretation grid used to infer long buildup, short buildup, short covering and long unwinding.
- SEBI derivatives-loss study. A study released in July 2025 reported that over 91 percent of individual traders in the equity derivatives segment lost money in FY25, with aggregate net losses of about ₹1,05,603 crore after transaction costs, roughly 41 percent higher than the prior year, underscoring how much of the loss concentrates in low-probability options.
Educational note. This guide explains how to read an option chain and what its columns do and do not tell you. It is not a recommendation to trade or invest, not a signal or a strategy, and it is not investment advice. Bharath Shiksha is an educational publisher, not a SEBI-registered investment adviser or research analyst.