Trading term

What is Vega?

Vega measures how much an option's price changes when implied volatility moves by 1 percentage point. A vega of 0.10 means the option gains about $0.10 if implied volatility rises 1 point. Vega is highest for at-the-money options with lots of time left, and it's why options get pricier when markets grow fearful.

Vega captures an option's sensitivity to volatility rather than to price or time. Because more expected movement means a higher chance the option pays off, rising implied volatility inflates the time-value portion of the premium — and vega tells you by how much. A vega of 0.10 means a 1-point rise in implied volatility adds about $0.10 to the option's price, whether or not the stock actually moves. Longer-dated, at-the-money options have the most vega, because they have the most time value for volatility to affect.

Vega is why options can gain or lose value with no move in the underlying at all. When fear spikes (say, before a crisis or an earnings report), implied volatility jumps and every option gets more expensive — good for holders, costly for buyers-to-be. When the event passes and volatility collapses (a 'volatility crush'), premiums deflate and long options can lose sharply even if the stock went their way. Understanding vega is essential for anyone trading around events, where volatility, not just price, drives the outcome.

Vega — sensitivity to volatility
premium ↑ as IV ↑low IV (10%)high IV (60%)An option's premium rises with implied volatility — vega is the slope of this line

Vega is how much the premium moves per 1-point change in implied volatility. Higher implied volatility inflates the premium (this rising line) — which is why options can gain or lose with no move in the stock.

For example

You buy an at-the-money call with a vega of 0.12 when implied volatility is 30%. If volatility jumps to 40% before earnings, the option gains about $1.20 (0.12 × 10 points) even if the stock hasn't moved — but if volatility then crashes back to 25% after the report, that gain reverses.

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Why it matters to you

Vega is the Greek that explains why options can win or lose with no move in the stock — because volatility itself has a price. For anyone trading around earnings or events, vega is often the dominant factor: buy when implied volatility is cheap, and beware paying up for options right before a 'volatility crush.'

⚠ Beware the volatility crush

The classic vega mistake is buying options right before a known event, when implied volatility — and vega-driven premium — is at its peak. After the event, volatility collapses, and the option can lose money even if the stock moved your way. High vega cuts both ways: you're exposed to volatility falling as much as rising.

Frequently asked questions

What is vega in options?

Vega measures how much an option's price changes for a 1-percentage-point change in implied volatility. A vega of 0.10 means the option gains about $0.10 if implied volatility rises 1 point. It captures an option's sensitivity to volatility, separate from price or time.

What is a volatility crush?

A volatility crush is a sharp drop in implied volatility, typically right after a known event like earnings. Because vega links premium to volatility, the crush deflates option prices — so a long option can lose money even if the stock moved in its favour. It's the main risk of buying options before events.

Which options have the most vega?

At-the-money options with plenty of time to expiration have the highest vega, because they carry the most time value for volatility to act on. Short-dated and deep in- or out-of-the-money options have little time value, so their vega is small.

How does vega relate to implied volatility?

Vega measures the option's price sensitivity to implied volatility; implied volatility is the volatility level itself. When implied volatility rises, vega tells you how much the premium increases. High-vega options are the ones most affected by swings in implied volatility.

Related terms

Call optionA call option is a contract giving the buyer the right — but not the obligation — to buy an asset at a fixed 'strike' price before a set expiry date. Call buyers are betting the price will rise; their risk is capped at the premium paid, while the potential profit is open-ended.Cash-secured putA cash-secured put is an options strategy where you sell a put option while setting aside enough cash to buy the stock if you're assigned. You collect the premium as income; in exchange, you agree to buy the stock at the strike if it falls there. It's a way to get paid to buy a stock you want at a lower price.Covered callA covered call is an options strategy where you own 100 shares of a stock and sell a call option against them. You collect the premium as income; in exchange, you cap your upside at the strike. It's a popular way to generate income on shares you're happy to hold or sell.DeltaDelta measures how much an option's price moves for each $1 change in the underlying. A delta of 0.60 means the option gains about $0.60 if the stock rises $1. It ranges from 0 to 1 for calls (0 to −1 for puts) and doubles as a rough probability the option finishes in the money.
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