The Put-Call Ratio (PCR)

For this three-strike window, OI PCR is 1.50. That is 1.5 outstanding Puts for each outstanding Call. Volume PCR is 0.50: half as many Puts as Calls traded in the stated period. The two readings differ because one counts what is open and the other counts what traded. The gap, or a crossing of 1, does not show a change in market direction.

These counts do not say who started a trade, or whether a contract is a hedge, part of a spread or a stand-alone position. They also do not show how easy it is to trade at a fair price. For that you need the bid and ask sizes and the spread. You do not need a lot size here. Multiply every count by the same number and it cancels out of the ratio.

On a real dashboard, read the field definitions and the actual observation times. Refreshing the page does not prove each field was just updated. OI is not always slow and volume is not always noise. Which one is useful depends on the question you are asking, not on a fixed ranking.

Now add a separate later expiry F across the same three strikes, at the same OI moment. Its totals are 40,000 Puts and 80,000 Calls, so PCR is 0.50. E and F together have 2,20,000 Puts and 2,00,000 Calls: PCR 1.10. The simple average of the two ratios is 1.00, and it is wrong. E has more Calls than F, so equal weights ignore the different sizes. Add the counts first, then divide.

The same rule applies across strikes. Averaging each strike's PCR gives every row the same weight, even when their Call counts differ. A row with zero Calls has no PCR of its own, but its verified Puts still belong in the Put total. Keep them whenever the total Call count is positive. Dropping the row quietly changes the calculation.

When you compare over time, keep the selection rule fixed. A fixed strike window follows the same named strikes. A window that moves with the index changes its members as NIFTY moves. An automatic switch from the near expiry to the next one changes the contracts too. Either can move PCR with no new activity in the old contracts. Record the new scope before you read the move.

Keep the units the same across the group. A count of contracts gives every contract equal weight, even if expiries carry different multipliers. Converting to underlying units is a different measure and must be labelled. Do not put contracts on one side and units on the other. And an all-expiry ratio is not interchangeable with a near-expiry ratio.

Now the reverse limit. Double both totals to 3,60,000 Puts and 2,40,000 Calls and PCR is still 1.50, though the count of open contracts has doubled. So an unchanged PCR does not mean nothing happened. It also cannot measure the market's total risk in money. Contracts differ in strike, expiry and sensitivity, and the count leaves out the rest of each portfolio.

A Put holder may be protecting a stock portfolio and still be bullish overall. A Put writer may hold other options or hedges. Both sit in the same contract, which OI counts once. Public Put totals do not say which purpose applies. Even if Put OI rose, that would not show buyers got fearful or writers got confident. The new contracts have both sides.

A contrarian reading says an unusually high Put-to-Call figure goes with too much worry, and prices may then turn up. A directional reading says it goes with a decline that continues. Neither follows from the count alone. To test one, first fix the data, the scope, the timing, what "unusual" means, the outcome and the horizon. A familiar 0.7 or 1.3 is not a universal NSE threshold, and this lesson gives no NIFTY band.

This is a point about evidence. It is not a claim that every option ratio is useless. Pan and Poteshman studied historical US stock-option volume, picking out buyer-initiated trades that opened positions, using P/(P + C). That is a different dataset and ratio from our unsigned public-chain P/C. It cannot prove that this NIFTY OI figure predicts a reversal. The contrary-reading examples from OIC are US teaching examples, not tested Indian signals.

A tiny bottom number is a third case. The ratio can be calculated but is very sensitive. Ten Puts and one Call give 10.00. One more Call and it is 5.00, with no change in Puts. Look at the totals beside the result before you call a big move market-wide sentiment. No minimum count is universal here, and the example proves no reversal. Completeness, the size of the denominator and comparability are separate checks.

Use the exchange time and timezone if given, and keep them apart from the provider's receipt time and the time you fetched the page. Keep OI snapshots apart from volume periods. Session volume is a running total, so a refreshed total replaces the earlier one. Never add them. Compare equal elapsed times, or a clearly matched start and end. Note any known delay.

When an expiry rolls, or a moving strike window changes its members, mark the boundary. Check that the historical baseline uses the same instrument, units, expiry and strike policy, measure and clocks before you blame a jump on new positioning. Keep both the Put and Call totals so a shrinking bottom number stays visible. A single "high PCR" label hides exactly these choices.

Write your hypothesis before you see the result. If you study direction, fix a price reference, a horizon, and the outcome that would prove the idea wrong. Keep the index move apart from the profit of an option position, which has its own contract, entry, exit and costs. A short journal builds consistent observation. It does not prove an edge. A forecast claim needs broader comparable data, fixed rules, and a test on data that did not choose them.

Lesson 24 asks a different question: it uses open contracts across strikes and an assumed settlement price at expiry. Carry forward the expiry, the strikes, the units and the time. PCR summarises relative counts. Max pain adds a made-up settlement calculation. Neither makes the contracts pull the price, and neither says where NIFTY will finish.