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How to read an option chain: OI, PCR and max pain without fooling yourself
The option chain is the most-watched screen in Indian markets and the most misread. Here is what each column really says, how PCR and max pain are calculated, and why the same chain can tell two traders opposite stories.
Open any trading app at 9:16 am and the first screen half of India looks at is the Nifty option chain. Columns of open interest, change in OI, volume and implied volatility promise to show where the big money stands. Read carefully, they do. Read carelessly, they confirm whatever you already believed. This guide is the careful version.
What each column means
An option chain lists every strike for one expiry, calls on the left and puts on the right, with the strike in the middle. The columns vary by platform, but the useful ones are always the same:
| Column | What it is | What it is not |
|---|---|---|
| Open interest (OI) | Contracts still open at that strike — positions that have not been closed | A count of today’s trades |
| Change in OI | Positions added or closed since yesterday’s close | A signal of direction on its own |
| Volume | Contracts traded today, opened or closed | New positions |
| LTP and change | Last traded premium and its move | A fair price for an illiquid strike |
| IV | The volatility implied by that strike’s premium | A forecast of direction |
OI is the column that matters most and the one most often misunderstood. Every open contract has a buyer and a seller, so a large OI number is not “bullish” or “bearish” by itself. What carries information is who is likely to be holding it, and that comes from reading OI together with price. If the terms are new, our open interest guide starts from first principles.
OI build-up: four patterns
Combine the change in price with the change in open interest and four patterns appear. They apply to futures directly and, with care, to individual option strikes:
| Price | Open interest | Usual reading |
|---|---|---|
| Up | Up | Long build-up — new buyers are entering |
| Down | Up | Short build-up — new sellers are entering |
| Up | Down | Short covering — sellers are closing out |
| Down | Down | Long unwinding — buyers are closing out |
On an option chain the most watched version is call and put writing. When call OI climbs at a strike while that call’s premium falls, sellers are adding positions there and are betting the index will stay below it; heavy call writing tends to mark resistance. Heavy put writing at a strike below the market tends to mark support for the same reason. These are probabilities, not walls: writers hedge, roll and get squeezed.
Put-call ratio, properly
The put-call ratio (PCR) is total put open interest divided by total call open interest for one expiry. In the example above it is 1.12. Some platforms use volume instead of OI; the two answer different questions, so check which one you are reading.
The usual rule of thumb says a PCR above about 1.2 reflects heavy put writing (support below, a firm market) and below about 0.7 reflects heavy call writing (resistance overhead). At extremes it is read the other way, as a contrarian sign that positioning has gone too far. Both readings are common, which tells you the number needs context:
- Track the change, not the level. A PCR rising from 0.8 to 1.1 over a session says more than a single reading of 1.1.
- Use the right expiry. The weekly contract and the monthly contract can carry very different ratios on the same day.
- Watch the strikes, not just the total. One deep out-of-the-money put strike stuffed with OI can lift the ratio without saying much about the market.
Max pain: the calculation and its limits
Max pain is the expiry price at which option buyers, in total, would lose the most — equivalently, the price at which the combined intrinsic value of all open calls and puts is smallest. To compute it, take each strike as a possible settlement price, add up what every call and put would be worth there, weighted by its OI, and pick the strike where that total is lowest. In our example the answer is 26,000.
The theory says writers, who are often larger and better hedged, pull expiry towards that level. The evidence is mixed. Max pain drifts during the week as positions change, it is computed from end-of-day OI unless you have intraday OI, and on a trending week the index simply walks away from it. Treat it as a reference line on expiry day, not a target. From 7 December 2026 expiry also settles on a 30-minute VWAP rather than the closing price — see our closing auction explainer.
IV and skew
Implied volatility is usually higher for out-of-the-money puts than for equally distant calls: protection against a fall is in demand. That slope across strikes is the skew. A steepening skew, with put IV rising faster than call IV, says the market is paying up for downside cover even if the index has not moved. The overall level of IV across the chain is summarised by India VIX, and the sensitivities that IV feeds into are covered in our option Greeks guide.
Five mistakes that cost money
- Reading OI as direction. Big call OI does not mean people are bullish; it usually means people sold calls.
- Trusting one snapshot. OI is updated through the day, but many free screens refresh slowly. A support level built from a stale snapshot is a guess.
- Ignoring the expiry calendar. Nifty weekly options expire on Tuesday and Sensex options on Thursday; OI patterns change completely in the last session. Our expiry-day guide explains why.
- Mixing up volume and OI PCR. They can point in opposite directions on the same morning.
- Forgetting liquidity. The last traded price of a far strike can be an hour old. Use bid–ask before trusting any premium-based number.
- OI counts open positions; read it with price, never alone.
- Call writing marks likely resistance and put writing likely support — as probabilities.
- PCR is puts over calls; track its change and know whether it uses OI or volume.
- Max pain is a reference line that drifts through the week, not a target.
- Live, intraday OI beats an end-of-day snapshot for every one of these readings.
Questions traders ask
How do you read an option chain?
Read open interest together with price: rising OI with a falling premium at a call strike indicates call writing (likely resistance), and the same at a put strike indicates put writing (likely support). Use change in OI, volume and IV to confirm, and always check which expiry you are looking at.
What is a good put-call ratio for Nifty?
There is no single good value. A PCR around 0.7 to 1.2 is typical; readings above about 1.2 reflect heavy put writing and below about 0.7 heavy call writing. Extremes are often read as contrarian signs. Watch how the ratio changes through the session rather than one reading.
How is max pain calculated?
For each strike as a possible expiry price, add up the intrinsic value of every open call and put weighted by its open interest. The strike where that total is lowest is max pain, the level at which option buyers as a group would lose the most.
Does Nifty expire at max pain?
Sometimes, but not reliably. Max pain changes during the week as positions change, and trending markets move away from it. It is best used as a reference level on expiry day, not a prediction.
Is OI data updated in real time?
Exchanges update open interest during the trading day, but many free screens refresh it slowly or only at intervals. For intraday analysis, use a feed that delivers OI updates as the exchange publishes them.
Which day do Nifty options expire?
Nifty weekly options on NSE expire on Tuesday; monthly contracts expire on the last Tuesday of the month. Sensex options on BSE expire on Thursday. If the day is a holiday, expiry moves to the previous trading day.
Live open interest, strike by strike
Option chains with OI updated as the exchange publishes it, streamed into NinjaTrader 8, AmiBroker and Excel. Five days free — no card, no auto-charge.
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