--- title: "IV rank vs IV percentile: definitions and an NSE example" description: "IV rank and IV percentile defined, worked on a year of Nifty 30 day implied volatility, with the series, window and tie choices that make two screens disagree." source_url: "https://www.rupeecase.com/learn/path-16/module-16-4-iv-rank-and-iv-percentile" --- [Path 16 4 of 16](/learn/path-16/)IV rank and IV percentile, done properly[Next 16.5](/learn/path-16/module-16-5-realised-volatility-estimators) Tuesday 15 Sep 2026, the last session in the data. The Nifty 30 day at the money implied volatility closed at 12.44 percent a year. A screen that ranks it over the past 252 sessions reads 18.5 percent. A screen that takes its percentile over the same sessions reads 63.1 percent. Same number, same series, same window. One says low and the other says above the middle. I check which of the two a screen is quoting before I read anything into it. This lesson takes both apart, on the same file. Every figure comes from NSE end of day files, so nothing here is live and nothing is a view on where volatility goes next. 3By the end you can 1. Calculate IV rank and IV percentile from a window of daily implied volatility. 2. Explain why one spike drags rank down while percentile barely moves. 3. Name the series, window and tie rule behind any rank or percentile you quote. ## The idea, plainly A raw implied volatility needs a yardstick. The [first volatility lesson](/learn/path-16/module-16-1-historical-vs-implied-volatility) said so, and [solving for implied volatility](/learn/path-16/module-16-3-solving-for-implied-volatility) showed how each day's number is made. Rank and percentile are the two common yardsticks. Both compare today's reading with the same series over a past window. They differ in how much of that window they use. Rank = (now minus low) divided by (high minus low) Percentile = days below now divided by days in window Readings: 12 13 12 13 14 12 13 30 13 14 Low 12, high 30, today 14 Rank = (14 minus 12) / (30 minus 12) = 11 percent Below 14: 7 of 10 = 70 percent Rank reads two days of the window. Percentile reads all of them The same 252 sessions of the Nifty 30 day at the money series, to 15 Sep 2026. Source: NSE end of day data, computed by RupeeCase. As of 15 Sep 2026. * **The series.** A constant maturity 30 day at the money implied volatility, or India VIX, is steady. The at the money implied volatility of the nearest expiry is not: it changes tenor every day and jumps when an expiry rolls off. * **The window.** Most screens use about a year of sessions. Shorter windows react faster and carry less history. * **The ties.** Percentile counts strictly lower days here. Some screens count lower or equal. 1. Keep the last N sessions of the series, with N the window you have chosen. 2. Find the lowest and the highest reading in those N sessions. 3. Put today's reading into the rank formula, with those two values. 4. Count the sessions strictly below today's reading and divide by N for the percentile. Read 10 more paragraphs, 450 words **Rank uses two days.** Only the lowest and the highest reading of the window enter the formula. It says where today sits on the line between them. **Percentile uses every day.** It counts the days when implied volatility was below today's, strictly below, and divides by the days in the window. A day that tied today's counts as not lower. A small invented case shows the split. Ten daily readings, nine of them between twelve and fourteen and one at thirty. Today is the last reading and it is fourteen. This is a teaching box with made up numbers, not market data. The same fourteen is near the bottom of the range and well above the middle of the crowd. Neither is wrong. They answer different questions, and the thirty is why they disagree. **IV rank or IV percentile: what is the difference?** Rank is a position in a range. Percentile is a position in a crowd. If one wild day sets the high of the window, rank squeezes every ordinary day into a thin band near the bottom. Percentile hardly notices, because that one day is one day. When the two disagree widely, the gap itself is the message: a single spike is setting the high. Three choices change either number. Say them whenever you quote one. A year of sessions holds one Budget, four results seasons and whatever else came along. If the year held a shock, every later reading is measured against it until it ages out of the window, and that takes a full window of sessions. Both measures carry that memory, and rank carries more of it. To build either one yourself you need one column of daily readings from one series, and four steps. Then change N and watch what moves. That is the fastest way to see which of the two depends on a spike. **What do IV and IVP mean in the option chain?** On the NSE chain, the IV column is the volatility solved from each strike's own price. The rank and percentile are not part of that chain. Many broker and analytics screens add them next to it, and they are built on a series of the index's implied volatility, not on the strike's own history. Which series, which window and which of the two they quote differ from screen to screen. The [question page](/learn/questions/iv-and-ivp-in-option-chain) has the short version and the [other one](/learn/questions/iv-rank-vs-iv-percentile) sets the two side by side. Neither number says options are cheap or dear. Both compare implied volatility with its own past. They do not compare it with the volatility that comes after, which is a different question and the subject of the [realised volatility module](/learn/path-16/module-16-5-realised-volatility-estimators). ## Worked example: 15 Sep 2026 The window is the 252 sessions from 9 Sep 2025 to 15 Sep 2026. Over it the 30 day implied volatility ran from a low of 8.62 on 24 Dec 2025 to a high of 29.22 on 30 Mar 2026. Today's 12.44 sits near the low end of that range. * **Range.** 29.22 minus 8.62 is 20.60 points. * **Today above the low.** 12.44 minus 8.62 is 3.82 points. * **Rank.** 3.82 over 20.60 is 18.5 percent. * **Days below 12.44.** 159 of 252, counted in the file. * **Percentile.** 159 over 252 is 63.1 percent. One spike in March 2026 sets the high of the whole window Percent a year. Computed by RupeeCase from NSE settlement prices of the two nearest monthly expiries, blended to thirty days. The marks are the low and the high that rank uses. Source: NSE end of day data, computed by RupeeCase. As of 15 Sep 2026. On 60 sessions the two agree. On the longest window the spike pulls rank far below percentile The 120 and 252 session windows both contain the 30 Mar 2026 high. The 60 session window does not, so rank and percentile land close together. Source: NSE end of day data, computed by RupeeCase. As of 15 Sep 2026. Another series shifts the answer by a few points, so name the series The at the money series is solved by RupeeCase from settlement prices. India VIX is NSE's index, built from a strip of out of the money options. Source: NSE end of day data, computed by RupeeCase. As of 15 Sep 2026. Read 5 more paragraphs, 293 words Look at how the 30 Mar 2026 high reshapes the rank. It stretches the range to 20.60 points, so today's reading above the low counts for little. But 159 of 252 days were below it, which is why the percentile sits above the middle. On the line chart the spike dwarfs everything around it. The window matters too. Shorten it, and both numbers move, but not equally. The 60 session window leaves the spike out, so rank at 71.6 and percentile at 76.7 land within a few points of each other. The two longer windows include it. Rank drops to 16.9 on 120 sessions and 18.5 on the full window, while percentile reads 40.8 and 63.1. Series matter as well. India VIX closed at 13.43 that day, with a rank of 22.8 and a percentile of 63.9 over the same 252 sessions. Read the two together. When both are low, implied volatility is low against its own history however you cut it. When both are high, the reverse. When rank is low and percentile is middling, as here, look at the chart for a spike before you read anything else into the pair. A screen that shows only one of the two hides that clue. Also note what the inputs are. The series is solved from settlement prices, so a stale or wide quote on one expiry can move a single day's reading, and that day then sits in every window that holds it. Switching from the at the money series to India VIX moved the rank by a few points here. On a screen that sorts or filters by rank, a few points can move a name across a line. Pick one series and one window, state both, and keep them. ## The common mistake The claim: IV rank below 50 means options are cheap, and above 50 means they are expensive. Rank says where today sits between the lowest and highest day of a window. It does not say what volatility will do next, and it does not compare implied volatility with the volatility that follows. The same implied volatility on 15 Sep 2026 read 18.5 on rank and 63.1 on percentile, and the 20 session realised volatility that day was 7.27. Three yardsticks, three different stories. Say "high against its own year" if that is what you mean, and name the series and window with it. ## Key takeaways * Rank places today between the window's low and high. * Percentile counts the days when implied volatility was lower than today. * One spike can pin rank low for months. Percentile hardly notices it. * State the series and the window. Both change the answer. * Neither says options are cheap or dear against the volatility that follows. * A wide gap between rank and percentile means one spike sets the high. 3 terms this section turns on From the module glossary; every term is in the Learn glossary too. Source: Module 16.4, IV rank and IV percentile, done properly. **Before you trade.** Derivatives trading carries a high risk of loss. SEBI's study "Profitability of Individual Traders in the Equity Derivatives Segment (FY25 to FY26)" (August 2026) found that 87.7% of individual traders in equity F&O made net losses in FY26, with aggregate net losses of Rs 91,685 crore. [Read the SEBI study](https://www.sebi.gov.in/reports-and-statistics/research/aug-2026/study-profitability-of-individual-traders-in-the-equity-derivatives-segment-fy25-fy26-_103835.html) What does IV rank and IV percentile, done properly cover?Two yardsticks for the same implied volatility. One reads two days of a window, the other reads all of them. It works through The idea, plainly, Worked example: 15 Sep 2026, The common mistake, Key takeaways. It is module 16.4 of Path 16, Volatility, about 9 minutes of reading, free. TTry it ## IV rank and percentile, on the same example. Both definitions side by side on a dated series. Dated NSE end of day data, nothing live, no orders. **IV rank and percentile**. [Open the iv rank and percentile](/learn/tools/iv-rank-percentile?series=nifty-atm-iv-30d) AF&O on RupeeCase ## Hedging only, in development F&O at RupeeCase will do one job: protect a portfolio you already own, by a rule published before it runs. No speculation, no naked option selling, no leveraged bets. It is not available yet. [How hedging will work](/hedging)[Sign up for RupeeCase](https://invest.rupeecase.com/signup) [No hedgeFalls with the marketWith a putA floor, for a premiumIllustration with made up numbers, not a product and not a recommendation.](/hedging) QQuick check ## 10 questions, 7 to pass. Each attempt draws 10 of the 15 questions in this module's bank, and a retake draws a fresh set. A pass gives this module's Certificate of Completion. Your result stays on this device and counts towards the Path 16 certificate. 7 of 10 correct passes module 16.4 Every answer is explained when you check; a retake is always free. Source: RupeeCase Learn quiz rules (70% to pass). Passed ### Certificate ID Download PNGPrint or save as PDF[Check the ID](/learn/certificates/verify) Self paced and unproctored. A record of completing free education by RupeeCase; not a NISM certificate and not endorsed by NISM, NSE, BSE or SEBI. It qualifies no one to deal, advise or publish research. CCheck yourself ## Path 16 so far. Your quick check results on this device, stop by stop. Stop 4 of 16 on Path 16 Volatility: every live stop, this module ringed. Source: RupeeCase Learn, Path 16. 1. [16.1Volatility: historical against impliedNot yet](/learn/path-16/module-16-1-historical-vs-implied-volatility) 2. [16.2India VIX for beginners: what it measures and what it does notNot yet](/learn/path-16/module-16-2-india-vix-explained) 3. [16.3Solving for implied volatilityNot yet](/learn/path-16/module-16-3-solving-for-implied-volatility) 4. [16.4IV rank and IV percentile, done properlyNot yet](/learn/path-16/module-16-4-iv-rank-and-iv-percentile#quiz) 5. [16.5Measuring realised volatility: four estimatorsNot yet](/learn/path-16/module-16-5-realised-volatility-estimators) 6. [16.6Events and IV crush: results, Budget, RBI and electionsNot yet](/learn/path-16/module-16-6-iv-crush-around-events) 7. [16.7Smile and skew: a first look at Nifty and stocksNot yet](/learn/path-16/module-16-7-volatility-smile-and-skew) 8. [16.8Skew measures: risk reversal, butterfly and slopeNot yet](/learn/path-16/module-16-8-skew-measures) 9. [16.9Term structure and event varianceNot yet](/learn/path-16/module-16-9-term-structure-and-event-variance) 10. [16.10Forward volatility from two expiriesNot yet](/learn/path-16/module-16-10-forward-volatility) 11. [16.11India VIX rebuilt step by stepNot yet](/learn/path-16/module-16-11-india-vix-rebuilt) 12. [16.12Forecasting volatility: EWMA, GARCH and HARNot yet](/learn/path-16/module-16-12-forecasting-volatility) 13. [16.13The variance risk premium in NiftyNot yet](/learn/path-16/module-16-13-variance-risk-premium) 14. [16.14Variance swaps and replicationNot yet](/learn/path-16/module-16-14-variance-swaps) 15. [16.15Volatility surface models: SVI, SABR, local and stochastic volNot yet](/learn/path-16/module-16-15-volatility-surface-models) 16. [16.16Skew dynamics: sticky strike against sticky deltaNot yet](/learn/path-16/module-16-16-skew-dynamics) 17. [TPath test, 30 questionsNot yet](/learn/path-16/module-16-16-skew-dynamics#pathTestSection) Path 16 in reading time: 159 minutes over 16 modules Minutes of reading per module, this one in amber. Source: RupeeCase Learn, Path 16. Explore next ## Put the module to work. * [ToolOption payoff builderLegs on a dated Nifty chain, breakevens and charges](/learn/tools/payoff-builder) * [Free module 16.1Volatility: historical against implied7 min read](/learn/path-16/module-16-1-historical-vs-implied-volatility) * [Free module 16.2India VIX for beginners: what it measures and what it does not8 min read](/learn/path-16/module-16-2-india-vix-explained) * [Free module 16.3Solving for implied volatility9 min read](/learn/path-16/module-16-3-solving-for-implied-volatility) * [Free module 16.5Measuring realised volatility: four estimators9 min read](/learn/path-16/module-16-5-realised-volatility-estimators) * [QuestionWhat do IV and IVP mean in the option chain?A short answer with a dated chart](/learn/questions/iv-and-ivp-in-option-chain) Community ## Join my WhatsApp group. Scan the code, fillFill one short form, and join my WhatsApp group. Slides, sources, factsheets and the rebalance logs live there, and members join a daily Google Meet with me. New to RupeeCase? [Getting started](/getting-started) [See the terminal](/terminal) [Sign up for RupeeCase](https://invest.rupeecase.com/signup) [Join the WhatsApp group](https://forms.gle/C6HMtM1Z2GfeocQV7) [One form, one group](https://forms.gle/C6HMtM1Z2GfeocQV7)Scan with your phone camera SSources ## Go to the source. 7 sources, NSE the most cited The publisher of each source listed below. Source: Module 16.4 source list. 1. [NSE, option chain (Nifty 50 index options)](https://www.nseindia.com/option-chain) NSE 2. [NSE, India VIX: index page and methodology](https://www.nseindia.com/static/products-services/indices-indiavix-index) NSE 3. [NSE, India VIX white paper](https://nsearchives.nseindia.com/web/sites/default/files/inline-files/white_paper_IndiaVIX.pdf) NSE 4. [NSE, derivatives end of day reports: F&O bhavcopy and participant wise open interest](https://www.nseindia.com/all-reports-derivatives) NSE 5. [NISM, Series VIII Equity Derivatives certification examination: test objectives](https://www.nism.ac.in/revamp-nism/test-objectives-revised-nism-series-viii-equity-derivatives-certification-examination/) NISM 6. [Carr, P. and Wu, L. (2009), Variance Risk Premiums, Review of Financial Studies](https://ideas.repec.org/a/oup/rfinst/v22y2009i3p1311-1341.html) Paper 7. Natenberg, S., Option Volatility and Pricing, McGraw Hill (volatility and its history) Book GTerms ## 5 terms from this module. IV rankWhere today's implied volatility sits between the lowest and highest reading of a past window, as a share of that range. IV percentileThe share of days in a past window when implied volatility was lower than today's. It counts days and ignores the size of the high and low. Constant maturityA volatility series that always looks thirty days ahead, built by blending the two nearest expiries, so it does not jump when an expiry rolls off. WindowThe stretch of past sessions a rank or percentile is measured over. About a year of sessions is common. TiesDays when implied volatility equalled today's. This lesson counts only strictly lower days in the percentile. [All 230 terms in the glossary](/learn/glossary) [Question people askWhat do IV and IVP mean in the option chain?A short answer with a dated chart](/learn/questions/iv-and-ivp-in-option-chain)[Question people askIV rank or IV percentile: what is the difference?A short answer with a dated chart](/learn/questions/iv-rank-vs-iv-percentile)[Related module16.1 Volatility: historical against implied7 min, Beginner](/learn/path-16/module-16-1-historical-vs-implied-volatility)[Related module16.2 India VIX for beginners: what it measures and what it does not8 min, Beginner](/learn/path-16/module-16-2-india-vix-explained)[Pillar guideDerivatives and Quant115 modules across paths 12 to 19](/learn/derivatives) Education only, not investment advice, a research report or a recommendation to buy, sell or hold any security. RupeeCase (QC Alpha Technologies Pvt Ltd) is not registered with SEBI as an investment adviser or research analyst. Contracts and prices shown are for illustration only, come from NSE end of day files at least 30 days old, and are not recommendatory. Derivatives trading carries a high risk of loss.