Options

How to read the NIFTY option chain: open interest and option chain analysis

12 min read

What the option chain shows

The option chain is a table of every call and put strike for one underlying and one expiry. For the NIFTY option chain, calls sit on the left, puts on the right and strike prices run down the middle. Each row shows the option's last price, volume, open interest, change in OI and implied volatility.

Option chain analysis is the practice of reading where positions are concentrated and how they change through the day. It helps traders understand where option writers expect resistance and support, how much movement the market is pricing, and when positioning starts to shift. This guide explains how to read the option chain from zero, then how to combine it with the price chart.

Option chain columns explained

Column	Meaning
Strike	The price at which the option can be exercised at expiry.
LTP	Last traded premium of the option.
Volume	Contracts traded today, opening and closing.
OI	Open interest: contracts still open.
Change in OI	How much OI has risen or fallen since the previous close.
IV	Implied volatility: the volatility the premium implies.
Bid / ask	Best prices buyers and sellers are quoting now.

Strikes below spot are in the money for calls and out of the money for puts; strikes above spot are the reverse. The strike closest to spot is at the money (ATM). Most intraday attention goes to the five to ten strikes either side of ATM.

Open interest: the core of option chain analysis

Open interest is the number of option contracts that have been opened and not yet closed or expired. Volume counts trades; OI counts positions. When a new buyer and a new seller trade, OI rises. When both close, OI falls. When one opens and the other closes, OI is unchanged.

Why OI is read through writers

Selling options requires much higher margin than buying them, so writers are usually larger and better-capitalised participants. Many traders therefore assume heavy OI at a strike reflects writers' positions. Writers profit if the option expires worthless, so they prefer price to stay away from their strikes.

• Heavy call OI above spot suggests call writers expect price to stay below that strike: a resistance area.
• Heavy put OI below spot suggests put writers expect price to stay above that strike: a support area.

This is an assumption, not a certainty. Some OI is bought as a hedge, and spreads involve both buying and selling. Treat writer-based readings as likely, and confirm with price.

Call and put walls: support and resistance from the option chain

The strike with the highest call OI above spot is often called the call wall; the strike with the highest put OI below spot is the put wall. Together they frame the range option writers are positioned for.

↻ ReplayIllustration

Strong vs weak walls

• A wall that keeps growing during the day, with change in OI positive, is stronger than one built yesterday and now shrinking.
• A wall close to spot matters more intraday than one 500 points away.
• A wall with falling premium and rising OI shows active writing; a wall with rising premium and falling OI shows writers covering, which weakens it.

When walls shift

If put OI starts building at a higher strike and the old put wall unwinds, writers are moving support up. If call OI piles up at a lower strike, resistance is moving down. These shifts often say more than the level of any single wall.

How to read the option chain step by step

1. Pick the expiry. The nearest weekly for intraday, the current monthly for swing context.
2. Find ATM and frame ten strikes either side.
3. Mark the highest call OI and put OI strikes: the walls.
4. Check change in OI at each strike. Where is fresh writing happening today?
5. Read price and OI together using the OI buildup table: long buildup, short buildup, short covering, long unwinding.
6. Check PCR overall and its change through the session. See PCR ratio.
7. Note max pain near expiry. See max pain.
8. Read the ATM straddle for the expected move.
9. Put it on the chart. Compare walls and expected range with chart levels before drawing conclusions.

Change in OI and OI buildup in the option chain

Total OI shows accumulated positioning. Change in OI shows what is happening today, which is usually more useful intraday.

Option premium	OI	Reading
Up	Up	Long buildup in that option: buyers adding
Down	Up	Short buildup: writers adding
Up	Down	Short covering: writers exiting
Down	Down	Long unwinding: buyers exiting

Remember that premium also falls with time decay and changes with implied volatility. A put premium can fall even when NIFTY is flat. Read option OI buildup alongside the direction of the underlying futures.

PCR, max pain and expected move

Put-call ratio

PCR = total put OI ÷ total call OI. Readings around 0.8–1.2 are commonly treated as balanced; very high or very low readings may point to crowded positioning. Change in PCR through the day is often more informative than its level.

Max pain

Max pain is the strike where option buyers together would recover the least at expiry. It is most relevant in the last sessions of a cycle and when OI is large on both sides.

Expected move from the straddle

The price of the ATM call plus ATM put, the straddle combined premium, approximates how far the market expects price to move by expiry. If NIFTY is 24,300 and the ATM straddle costs 180, the market is pricing roughly a 180-point move either way. Breaks beyond that range are notable.

Implied volatility

Rising implied volatility means options are getting more expensive, often ahead of events or during sharp moves. Falling IV suggests calmer expectations. IV also affects how quickly premiums react to price.

Option chain analysis for intraday trading

Intraday, the option chain is best used as a map of where positioning sits, while the price chart and order flow show what is happening now.

• Morning: note opening walls, PCR and straddle price. These frame the expected range.
• First hour: watch where fresh writing builds. Put writing building under price while price holds supports the idea of buyers defending.
• Midday: look for walls shifting. Call writers moving lower while price stalls is a change in tone.
• Afternoon: as expiry nears, gamma effects grow; see gamma exposure.

Combine walls with chart levels from key levels and liquidity and the footprint from order flow. A put wall that lines up with the previous day's value area low and shows buyers absorbing on the footprint is a much clearer area than any of the three alone.

Worked NIFTY option chain example (illustration)

The figures below are invented for illustration.

At 9:30 IST NIFTY spot is 24,320. The weekly chain shows the highest call OI at 24,400 and the highest put OI at 24,200. PCR is 0.96. The ATM 24,300 straddle trades at 170, implying roughly 24,150 to 24,490 by expiry.

By 11:00, put OI at 24,300 has jumped and its premium has fallen while price held above 24,300: fresh put writing. Call OI at 24,400 is also rising. PCR climbs to 1.08. Writers are framing a 24,300–24,400 range.

At 13:15 price pushes to 24,395. Call OI at 24,400 stops rising and begins to fall while the 24,400 call premium rises: short covering by call writers. Futures delta turns strongly positive. A trader reads this as the call wall weakening. If OI then builds at 24,500 calls and 24,400 puts, the range is being reset higher. If price falls back and 24,400 call OI rebuilds, the wall has held.

The point is not the outcome but the process: walls, change in OI, PCR and price read together.

Option chain on expiry day

Expiry day changes how the NIFTY option chain behaves. Out-of-the-money premiums decay quickly, so OI at far strikes often collapses as positions are closed or simply left to expire. Walls near spot can become very strong because writers there have the most to lose, and large OI around one or two strikes can pin price for hours.

At the same time, cheap premiums attract buyers looking for a sharp move, and when a wall breaks, writers covering their positions can accelerate price quickly. That is why expiry sessions often alternate between dull ranges and sudden bursts. Traders reading the chain on expiry day pay closest attention to change in OI at the two or three strikes nearest spot, the straddle price decaying through the day, and whether futures order flow is pressing into a wall or fading away from it.

BANKNIFTY option chain differences

The BANKNIFTY option chain uses the same logic but tends to show larger point moves, wider straddle prices and faster shifts in OI. Strike gaps are larger, so walls are spaced further apart. Because BANKNIFTY moves more in points, a wall 300 points away may be more relevant than it would be on NIFTY. Always compare BANKNIFTY readings with its own history.

Common option chain analysis mistakes

• Treating walls as fixed. Walls move as writers roll and cover.
• Reading far OTM strikes intraday. Far strikes are often hedges; focus near the money.
• Ignoring the futures premium. If you trade futures, option strike levels sit lower than the futures price by the basis. See futures basis.
• Mixing expiries. Weekly and monthly positions answer different questions.
• Acting on OI alone. OI updates are delayed and batched; always confirm with price.
• Underestimating risk. Trading F&O carries a high risk of loss; premiums can lose value fast on expiry day.

Seeing it on the TradingMarble chart

TradingMarble shows a live NIFTY and BANKNIFTY option chain with OI, change in OI, PCR and straddle price beside the chart, and can place heavy OI strikes on the price chart so you see walls next to structure and volume profile. The footprint shows how buyers and sellers act when price reaches those strikes. See plans for availability.

Option chain checklist

1. Expiry selected; ATM and ten strikes either side framed.
2. Call wall and put wall marked; change in OI checked at both.
3. OI buildup read at key strikes, with IV and time decay in mind.
4. PCR level and change noted.
5. Straddle-based expected range recorded.
6. Max pain checked near expiry.
7. Everything compared with chart levels and order flow.

Learning how to read the option chain turns a dense table into a clear map of positioning. Used with price structure, option chain analysis helps you see where NIFTY and BANKNIFTY participants are committed and when that commitment begins to change.

Frequently asked questions