# IV Chart — StockMojo

> Implied Volatility trend over time with IV Rank and Percentile

- Live page: https://stockmojo.in/iv-chart
- Content last updated: 2026-04-11
- Platform: StockMojo — free options analytics for Indian markets (NSE F&O)

This is a machine-readable markdown mirror of the live tool page. The live page shows real-time NSE data during market hours (09:15-15:30 IST) and supports 200+ F&O symbols via per-symbol URLs like https://stockmojo.in/iv-chart/banknifty.

## Frequently asked questions

### What is implied volatility (IV) and why does it matter?

Implied volatility is the market's forward-looking estimate of how much an underlying will move, derived by reverse-engineering an option pricing model from current option prices. It directly determines option premium: high IV means expensive options, low IV means cheap options. IV is the most important variable in option pricing apart from the underlying price itself.

### How is IV calculated for an option?

Given the option's market price, strike, time to expiry, underlying price, and the risk-free rate, you solve the Black-Scholes equation backwards for the volatility input that produces the observed price. This is done numerically — there's no closed-form solution. StockMojo computes IV per strike, per option type on every NSE tick.

### What is IV Rank vs IV Percentile?

IV Rank scales the current IV linearly between the past 52 weeks' high (100%) and low (0%). IV Percentile counts the percentage of trading days in the past year when IV was below today's reading. IV Rank reacts faster to extremes; IV Percentile is more stable. Most premium-selling strategies use IV Rank above 50% as an entry filter.

### What does a sudden IV spike mean before earnings or events?

Pre-event IV spikes reflect uncertainty pricing — the market knows a binary outcome is coming and demands extra premium for the risk. After the event resolves, IV typically collapses back to normal levels regardless of whether the actual move was large or small. This collapse is called IV crush.

### How does IV relate to option premium pricing?

Option premium has an intrinsic component (in-the-money value) and an extrinsic component (time value). IV directly inflates or deflates the extrinsic component. Two ATM options on the same underlying with the same time to expiry can have very different premiums if IV has changed — even when the underlying hasn't moved at all.

### What is 'IV crush' and when does it happen?

IV crush is the rapid collapse of implied volatility after an event resolves the uncertainty that was inflating it. It's most dramatic after corporate earnings, central bank meetings, and major macro releases. Long option positions can lose money even when the underlying moves the predicted direction, simply because IV crashes faster than the directional gain.

### Should I sell options when IV is high?

Generally yes — selling premium is statistically favored when IV is elevated, since the high IV inflates the premium you collect and historical realized volatility usually fails to live up to the implied expectation. Practitioners use IV Rank above 50% (and often above 75%) as a filter for premium-selling strategies. Always pair high-IV selling with strict risk management.

### How can I use the IV chart to time entries?

Look for IV at relative extremes versus its 52-week range. Entering long options at low IV (cheap premium) and short options at high IV (expensive premium) systematically improves expectancy over time. The StockMojo IV chart overlays historical volatility (HV) so you can see whether IV is pricing in more or less than what's actually been realized.

## How to use the StockMojo IV Chart

1. **Select an underlying** — Choose Nifty, BankNifty, or any F&O stock from the symbol selector.
2. **Read the current IV reading** — The chart shows IV plotted over time. Note the latest value and where it sits relative to the visible range.
3. **Check IV Rank and IV Percentile** — Look at the IV Rank and IV Percentile metrics displayed beside the chart. Values above 50% suggest elevated IV; below 50% suggest depressed IV.
4. **Compare IV vs HV** — Toggle the historical volatility overlay. A wide gap (IV well above HV) signals overpriced options; a narrow or inverted gap signals underpriced options.
5. **Pick your strategy bias** — Use the IV regime to bias toward premium selling (high IV) or premium buying (low IV) before entering a trade.

## Related tools

- [IV vs HV](https://stockmojo.in/iv-hv) — markdown: https://stockmojo.in/iv-hv.md
- [Volatility Skew](https://stockmojo.in/volatility-skew) — markdown: https://stockmojo.in/volatility-skew.md
- [Option Chain](https://stockmojo.in/option-chain) — markdown: https://stockmojo.in/option-chain.md

## Glossary

Terms used: implied-volatility, iv-rank, iv-percentile, historical-volatility. Definitions: https://stockmojo.in/glossary