# Vega Analysis — StockMojo

> Intraday total Call Vega vs Put Vega across ATM strikes

- Live page: https://stockmojo.in/vega-analysis
- Content last updated: 2026-06-01
- 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/vega-analysis/banknifty.

## Frequently asked questions

### What does the Vega Analysis tool show?

It plots two intraday lines — total Call Vega and total Put Vega — for a band of strikes around ATM. For every minute of the session it solves implied volatility from each option's traded price, reads the option's vega, then sums the vega of all selected calls into one line and all selected puts into another. The result is how your volatility exposure across near-ATM strikes evolved through the day.

### Why are Call Vega and Put Vega plotted separately?

In the Black-Scholes model vega is the same for a call and a put at the same strike and IV. In the real market, however, the call and put at a strike trade at different implied volatilities (the skew), so their vegas diverge. Splitting the two lines lets you see whether call-side or put-side volatility exposure is dominating, and how that balance shifts intraday.

### How is the ATM strike chosen?

ATM is taken from the live option chain: the tool reads the spot/future level and snaps to the nearest available strike. The 'Strikes around ATM (±)' selector then builds a symmetric window around that ATM strike — for example ATM ± 3 covers seven strikes, each with its call and put.

### Why is the strike range capped at ATM ± 4?

The intraday price API returns at most 20 option legs in one request. Because the tool fetches both the call and the put for every strike, ATM ± 4 is nine strikes × 2 = 18 legs, which is the largest symmetric window that stays within the limit.

### Is vega here per share or per lot?

Vega is reported per unit of the underlying, per one percentage-point change in implied volatility — the standard Black-Scholes convention. Multiply by the contract lot size if you need the rupee vega of a full position.

### Can I see how vega behaved on a past session?

Yes. Switch to Historical mode and pick a trading day. The tool replays that day's intraday option prices and rebuilds the Call and Put Vega lines exactly as they would have appeared live — useful for studying how volatility exposure reacted around events or expiry.

## How to use Vega Analysis

1. **Pick the underlying** — Choose Nifty, BankNifty, or any F&O stock from the symbol selector.
2. **Choose live or historical** — Live streams the current session. Historical lets you replay a past trading day.
3. **Select the expiry** — Pick the expiry whose strikes you want to analyse.
4. **Set the ATM range** — Choose how many strikes around ATM to include (ATM ± 1 up to ATM ± 4). Both call and put are included for each strike.
5. **Read the two vega lines** — Watch total Call Vega vs total Put Vega through the day. A widening gap signals call/put volatility-exposure imbalance driven by skew.

## Related tools

- [Volatility Skew](https://stockmojo.in/volatility-skew) — markdown: https://stockmojo.in/volatility-skew.md
- [IV Chart](https://stockmojo.in/iv-chart) — markdown: https://stockmojo.in/iv-chart.md
- [Multi-Strike Chart](https://stockmojo.in/multistrike-chart) — markdown: https://stockmojo.in/multistrike-chart.md

## Glossary

Terms used: vega, implied-volatility, option-greeks, volatility-exposure. Definitions: https://stockmojo.in/glossary