Open your broker's option chain for the first time and the IV column looks like just another number sitting next to price and open interest. It isn't decoration. It's the market telling you how much movement it's pricing into that exact strike before expiry, and reading it wrong is how a lot of traders end up buying an "expensive" option without knowing why it's expensive.
What Does IV Mean in the Option Chain
IV in an option chain is the implied volatility priced into that specific strike's premium. It's an annualized percentage that says how much the market expects the underlying to swing before expiry, and it isn't a single number for the whole stock or index. Every strike, every expiry, and every call/put pair carries its own IV, because each one is a separate bet on how much room the price needs to move.
Higher IV means the market is pricing in bigger swings, so the premium for that option costs more. Lower IV means the market expects a calmer ride, so the premium is cheaper. The reason IV moves the premium at all is Vega, the Greek that measures how much an option's price changes for every 1% move in IV.
Key takeaway: The IV number next to a strike tells you how much movement the market has priced in for that strike by expiry. It says nothing about direction, and nothing useful until you compare it against something.
Why IV Is Different for Every Strike (the Skew)
IV isn't flat across a chain. It shifts as you move away from the current strike price, and that shift is called skew. On index options like Nifty, strikes below the spot price usually carry a slightly higher IV on the put side than strikes above spot carry on the call side, because more traders are buying downside protection than upside speculation.
Here's an illustrative snippet of a Nifty chain with spot near ₹24,800 (numbers are for teaching, not a live quote):
| Strike | Call IV | Put IV |
|---|---|---|
| 24,600 | 12.6% | 15.4% |
| 24,700 | 12.3% | 14.0% |
| 24,800 (ATM) | 12.0% | 12.3% |
| 24,900 | 12.6% | 12.9% |
| 25,000 | 13.5% | 12.7% |
Notice the ATM strike sits at the bottom of the curve, and IV rises as you move to either wing, more sharply on the put side. That shape is the skew. It exists because option prices reflect real demand: a fund manager hedging a large portfolio buys puts, not calls, and that demand pushes put IV up independently of what calls are doing at the same distance from spot.
Skew also shows up across expiries, not just strikes. A stock's monthly options can carry different IV than its next-month options even for the identical strike, especially around events that fall inside one expiry but not the other.
High IV vs Low IV in the Option Chain
A raw IV number doesn't tell you whether it's high or low. 30% IV is unremarkable for a volatile mid-cap stock and alarming for Nifty. You need something to compare it against, and that's what IV Rank (or IV Percentile) does: it places today's IV somewhere on that stock's own IV history, usually the past year.
Say a semi-urban trader gets a tip on a WhatsApp group: "IV on this stock is 45%, buy the calls before it explodes." Without context that number means nothing. If that stock's IV has ranged between 35% and 70% over the past year, 45% sits on the lower end, an IV Rank around 25%, not the extreme the tip implied. If the same stock usually trades between 20% and 40%, that same 45% would actually be elevated.
As a rough anchor at the time of writing: Nifty's ATM IV typically sits in the 11-14% range in calm markets, and individual stocks range much wider depending on sector and beta. A stable large-cap might sit at 20-25% while a high-beta mid-cap can run 40%+. Check the live figures on your broker's chain rather than treating these as fixed, since IV moves with the market every day.
Why IV Spikes and Falls
IV isn't static. It rises ahead of known events and drops once the uncertainty clears, a pattern worth watching whenever you're reading a chain close to a big date.
- 1
Two weeks before the Union Budget, Nifty ATM IV sits around a calm 12-13%.
- 2
As the date nears, IV climbs to 18-20% as traders price in a bigger possible move on the day.
- 3
The morning after the Budget, once the announcement is out, IV drops back to 12-13% within hours.
That post-event drop is called IV crush, and it catches out traders who buy options right before a known event expecting a big move. Even if the price does move, the premium can still lose value because the IV component collapses faster than the price gain adds it back. The same pattern shows up around company results, RBI policy days, and elections, on a smaller or larger scale depending on how much the event actually matters to that underlying.
How to Actually Use the IV Column When Reading a Chain
Reading the IV column well comes down to three checks, not one glance at a single number.
- Check IV Rank or Percentile, not raw IV. A tool like Sensibull, or the analytics view built into Zerodha Kite or Upstox, will place today's IV against the stock's own recent range. High rank suggests premiums are relatively rich; low rank suggests they're relatively cheap, useful context if you're choosing between buying and selling premium.
- Look at the skew, not just the ATM number. If put IV is running noticeably hotter than call IV at similar distances from spot, that's the market leaning toward downside hedging demand, not a prediction that price will fall.
- Never read IV as a direction signal. IV tells you how big a move is priced in, not which way. A Mumbai-based equity investor moving into options for the first time often makes this mistake, since a rising number on a screen feels like a "buy" signal the way a rising stock price does. IV rising just means the market expects more movement, up or down.
Common Misunderstandings
High IV means the market expects the price to go up.
IV measures how big a move is priced in, not which direction it goes.
A strike with lower IV is a cheaper, better option to buy.
Lower IV just means less movement is priced in, not that the trade is better on its own.
IV should be roughly the same across every strike and expiry on the same stock.
IV varies by strike (skew) and by expiry (term structure), even on the same underlying.
Keep Reading
- How Are Option Premiums Calculated? — covers how IV feeds into the actual premium number, if you want the pricing mechanics behind what the chain shows
- Put Call Ratio (PCR) Explained — another chain-reading skill, using open interest instead of IV to gauge positioning