# Vega

> Vega measures how much an option's price changes for a 1 point move in implied volatility. Learn how it varies by expiry and why it matters around events.

Source: https://learn.tradelabsai.com/options/vega/  
Track: Options · Level: Advanced · Updated: 2026-10-03  
Publisher: TradeLabs AI (https://tradelabsai.com). Education, not financial advice.  
Cite as: TradeLabs Learn, "Vega", https://learn.tradelabsai.com/options/vega/

Vega measures how much an option's price changes when implied volatility changes by one percentage point. If a call has a vega of 0.15, a rise in implied volatility from 25% to 26% adds about $0.15 to its price, or $15 per contract. Vega matters because implied volatility can move a lot, especially around earnings and market stress, and those moves can make or lose money on an option position even when the underlying price stays still.

## Vega basics

| Position | Vega | Benefits from |
|---|---|---|
| Long call or put | Positive | Rising implied volatility |
| Short call or put | Negative | Falling implied volatility |
| Highest | At the money, long dated options | |
| Lowest | Short dated, far in or out of the money options | |

Calls and puts at the same strike and expiry have the same vega.

## Vega and time to expiry

Unlike gamma and theta, which grow as expiration nears, vega grows with time to expiry. A one year option is far more sensitive to volatility changes than a one week option. For at the money options, vega is roughly proportional to the square root of time.

**Example: Vega across expiries**
For a $100 stock with implied volatility near 25%, at the money calls have approximate vegas:

| Expiry | Approximate vega per share | Per contract |
|---|---|---|
| 1 week | 0.06 | $6 |
| 1 month | 0.11 | $11 |
| 3 months | 0.20 | $20 |
| 1 year | 0.40 | $40 |

A 5 point jump in implied volatility adds about $55 to a one month contract and about $200 to a one year contract.

These figures follow from the approximation that an at the money option's vega per share is about 0.4 × price × √(time in years) divided by 100.

## Volatility crush

Implied volatility often rises before scheduled events such as earnings and falls sharply afterwards. Option buyers can be right on direction and still lose because the drop in volatility, multiplied by vega, outweighs the gain from the move.

**Example: Earnings and vega**
Before earnings, a stock is at $50 and a one week $50 call costs $2.40 with implied volatility of 80% and vega 0.03. After the report, the stock rises to $51 and implied volatility drops to 35%. Vega effect: about 45 points × 0.03 = minus $1.35. Delta effect: about +$0.55. The call ends near $1.60 before counting a day of decay, a loss despite the rise. See [Volatility Crush and Expansion](https://learn.tradelabsai.com/volatility/volatility-crush-and-expansion/).

## Vega and strike

Vega is largest at the money and smaller for strikes far from the current price. Because implied volatility differs across strikes, a phenomenon known as skew, the vega exposure of a multi strike position depends on how the whole volatility curve moves, not just one number. See [Volatility Smile and Skew](https://learn.tradelabsai.com/volatility/volatility-smile-and-skew/) and [Volatility Surface](https://learn.tradelabsai.com/volatility/volatility-surface/).

## Using vega

| Goal | Position | Lesson |
|---|---|---|
| Profit if volatility rises | Long options, long straddles | [Straddle](https://learn.tradelabsai.com/options/straddle/) |
| Profit if volatility falls | Short options, iron condors | [Iron Condor](https://learn.tradelabsai.com/options/iron-condor/) |
| Long volatility in the back month, short in the front | Calendar spreads | [Calendar Spreads](https://learn.tradelabsai.com/options/calendar-spreads/) |
| Isolated volatility exposure | Variance swaps | [Variance and Volatility Swaps](https://learn.tradelabsai.com/volatility/variance-and-volatility-swaps/) |

Volatility traders manage vega as their main exposure, often hedging delta. See [Vega Positioning](https://learn.tradelabsai.com/options/vega-positioning/) and [Volatility Trading](https://learn.tradelabsai.com/volatility/volatility-trading/).

## Vega in portfolios

Vega adds across positions, but options of different expiries do not move in step: short dated implied volatility usually moves more than long dated. Many traders weight vega by expiry to reflect this. See [Volatility Term Structure](https://learn.tradelabsai.com/volatility/volatility-term-structure/) and [Managing Portfolio Greeks](https://learn.tradelabsai.com/options/managing-portfolio-greeks/).

## Common mistakes

- **Buying options before events** without accounting for volatility crush.
- **Ignoring vega on long dated options,** which can swing a lot with volatility.
- **Treating all vega as equal** across expiries.

## Frequently asked questions

### What is vega in options?

The change in an option's price for a one percentage point change in implied volatility.

### Why do my options lose value after earnings even if the stock moves my way?

Implied volatility usually falls sharply after earnings. The drop, multiplied by vega, can outweigh the gain from the price move.

### Which options have the highest vega?

At the money options with a long time to expiration.

Next, learn the smallest of the main Greeks, [Rho](https://learn.tradelabsai.com/options/rho/).

## Continue learning

- Next lesson: [Rho](https://learn.tradelabsai.com/options/rho/)
- Previous lesson: [Theta](https://learn.tradelabsai.com/options/theta/)
- Related: [Theta](https://learn.tradelabsai.com/options/theta/): Theta measures how much an option loses in value each day as time passes. Learn how decay speeds up near expiry and why sellers collect what buyers pay.
- Related: [Implied Volatility (IV)](https://learn.tradelabsai.com/volatility/implied-volatility/): Implied volatility is the market's forecast of future movement, backed out from option prices. Learn how to read it, convert it to expected moves and use it.
- Related: [Volatility Crush and Expansion](https://learn.tradelabsai.com/volatility/volatility-crush-and-expansion/): Implied volatility tends to rise before events and collapse after them. Learn why volatility crush happens, how to measure it and how to trade options around events.
- Related: [Vega Positioning](https://learn.tradelabsai.com/options/vega-positioning/): Vega positioning builds option trades to profit from rising or falling implied volatility. Learn long and short vega structures, term structure and how to size them.
- Related: [Volatility Trading](https://learn.tradelabsai.com/volatility/volatility-trading/): Volatility trading profits from the size of price moves, not their direction. Learn implied vs realised bets, the main instruments and how to manage risk.