Reading the option chain

The option chain is the most-screenshotted and least-understood table in Indian retail trading. It gets treated as a crystal ball: max call OI at 24,500, so the market cannot cross 24,500.

That reading is wrong, and the way it is wrong is instructive.

The chain does not tell you where price is going. It tells you where people are positioned. Those are different claims, and only the second one is supported by the data.

What each column is#

Switch between the three views and read what each one is actually reporting.

Open interest is the number of contracts currently open at that strike. Not volume — volume counts trades during the day, OI counts positions still standing. High OI means a lot of capital is committed there.

Change in OI is how that number moved today. It is fresher and usually more informative than the raw level.

Implied volatility is what the market is charging for uncertainty at that strike. Notice it is higher at the wings than at the money — the volatility smile.

Reading open interest honestly#

The standard interpretation goes: heavy call OI above spot is resistance, heavy put OI below spot is support.

There is a real mechanism underneath this. Option writers hedge. If a large number of calls have been written at 24,500, the writers are typically short those calls and hedged in the underlying. As spot approaches that strike, their hedging tends to dampen movement through it.

So the level is not superstition. But three things are usually left out:

OI does not say who. A high number at a strike could be writers expecting price to stall, or buyers expecting a breakout. The chain shows contracts, not intentions.

OI is not static. Those positions can be closed, rolled, or added to in an hour. Monday's wall can be gone by Wednesday.

Levels break, and break hard. When price does push through a heavy OI strike, the writers' hedging can accelerate the move rather than resist it. The level that looked like a ceiling becomes an amplifier.

Change in OI is the better signal#

The level of OI tells you where positions have accumulated. The change tells you what happened today. Combined with price direction, it identifies what kind of activity you are seeing:

This is a genuinely useful table, and it explains something that otherwise looks strange: rallies driven by short covering tend to fade. Nobody bought with conviction; people simply stopped being short. When the covering finishes, so does the move.

PCR, and what it is worth#

The put-call ratio divides total put OI by total call OI.

The textbook reading is contrarian: high PCR means excessive pessimism, which is bullish; low PCR means excessive optimism, which is bearish.

Treat this loosely. PCR has three problems worth knowing:

• No fixed thresholds. "High" only means anything relative to the recent range for this instrument.
• It mixes intentions. A put can be a bearish bet or a protective hedge on a long portfolio. Both land in the numerator and mean opposite things.
• It is aggregate. A single strike with unusual activity can move the whole ratio without telling you anything about the broader market.

PCR is best used as one input among several, and mostly for spotting extremes. As a standalone signal it is close to noise.

The volatility smile#

Look at the IV column again. Strikes far from spot show higher implied volatility than the at-the-money strike.

This is not an error. The market knows returns are not normally distributed — crashes are more common and more severe than a textbook bell curve predicts. So the market charges extra for far out-of-the-money options, particularly puts.

The practical consequence: far OTM options are relatively expensive, not cheap. Their low rupee price hides a high volatility price. When you buy a ₹8 weekly option, you are paying a premium rate for a lottery ticket, not finding one that is mispriced.

A working routine#

When you open a chain, go in this order:

1. Find ATM. The strike nearest spot. This anchors everything else.
2. Note ATM IV. Is volatility high or low relative to recent days? This decides whether buying or selling is structurally favoured.
3. Scan OI for concentration. Where are the walls, above and below? Note them as levels of interest, not barriers.
4. Check change in OI against price. Which of the four boxes in that table are you in? This is where the real information is.
5. Glance at PCR. Only to see whether it is at an extreme. Do not build a trade on it alone.

That routine takes under a minute and will keep you out of the confident wrong conclusions the chain invites.

Check yourself

0 of 4 answered

1. 1.Nifty rises 200 points and total call open interest falls sharply. What is the most likely explanation?

   Fresh buying is driving the moveShort covering — call writers are closing positionsNew call writers are entering aggressivelyThe exchange reduced the lot size

2. 2.Max call OI sits at 24,500 with spot at 24,018. What does this justify concluding?

   Nifty cannot close above 24,500 this expiryA large number of contracts are committed at that strikeInstitutions are bearish on the index24,500 will definitely be tested

3. 3.A far out-of-the-money weekly call costs just ₹8. Compared with the at-the-money call, it is:

   Cheaper in every meaningful senseLower in rupee price but carrying higher implied volatilitySafer because less capital is at riskBetter value because the payoff multiple is larger

4. 4.Why is PCR a weak standalone signal?

   It is calculated only once a dayIt ignores option premiums entirelyPuts can be directional bets or portfolio hedges, and both look identical in the ratioIt is only available for index options

What to take away

• The chain shows positioning, not destination.
• Change in OI with price direction beats raw OI for reading what is happening now.
• Short-covering rallies fade; fresh-long rallies have money behind them.
• PCR is a coarse extremes indicator, not a signal.
• The volatility smile makes far OTM options relatively expensive, however cheap they look.