What is Put-Call Ratio (PCR)?

PCR (OI) = total put OI ÷ total call OI, summed across every strike of one expiry. If NIFTY puts have 9.1 crore contracts open and calls have 7 crore, PCR is 1.3.

There are two other versions. Volume PCR divides put volume by call volume for the day. PCR of OI change divides today's put OI change by today's call OI change and reacts faster during the session. A strike-wise PCR divides one strike's put OI by its call OI.

In Indian index options most OI is created by writers, not buyers. So a PCR above 1 (more puts written) is usually read as support below and a bullish tilt, and below 1 as resistance above and a bearish tilt.

At extremes it flips. A PCR far above normal can mean the market is stretched on the upside and due for a pause, and a very low PCR the opposite. Read PCR with price and with where the OI sits, not on its own.

There is no single good number, but many traders treat roughly 0.8 to 1.2 as neutral, above 1.2 as bullish and below 0.8 as bearish. The AOC spot price bar uses exactly these bands: green above 1.2, red below 0.8, blue in between. On expiry day PCR swings sharply as positions are closed, so it means less then.

PCR changes every few minutes during market hours, so any number written on a page is out of date. The free AOC page at /optionchain/nifty shows the current NIFTY PCR with a 15-minute delay, along with max pain and the highest call and put OI strikes. The live chain shows it in real time with its intraday chart.

The overall PCR colours the spot price bar. Each strike row also shows its own PCR of OI and PCR of OI change under the strike, and that line turns red when the strike PCR drops below 0.75. Below the chain, the PCR OI and PCR OI Change cards open intraday charts so you can see the trend rather than one reading.