By the FinLingo Team | Capital markets practitioner, front office experience at a major European investment bank. FinLingo covers 342 lessons from bonds to exotic derivatives. About · Last updated:
Vega (ν) measures how much an option's price changes when implied volatility moves by 1 percentage point. A vega of 0.15 means the option gains $0.15 if implied vol rises from 20% to 21%, and loses $0.15 if vol drops from 20% to 19%. Unlike delta and gamma, vega is not a Greek letter — but it is arguably the most important sensitivity for volatility traders.
Both calls and puts have positive vega. Buying any option makes you long volatility: you benefit when implied vol rises and suffer when it falls. Selling options makes you short vega. This is independent of direction — you can be long vega and delta-neutral simultaneously. Understanding this is the foundation of volatility trading.
Time to expiry: longer-dated options have higher vega because there is more time for volatility to affect the outcome. A 1-year ATM call might have vega of 0.40; a 1-month ATM call might have 0.12. Moneyness: ATM options have the highest vega. Deep ITM and OTM options are less sensitive to vol because their outcome is already largely determined. The formula: ν = S · N′(d1) · √T.
You hold a portfolio of ATM calls with total vega of $50,000. This means a 1-point increase in implied vol adds $50,000 to your P&L, and a 1-point decrease costs $50,000. If implied vol drops from 25% to 22% overnight (a 3-point move), you lose $150,000. This is the daily reality for options traders — vega exposure often dominates delta exposure in terms of actual P&L impact.
Vega measures sensitivity to implied volatility, not realised. A stock can move a lot (high realised vol) while implied vol drops — your vega position loses money even though the market is volatile. This disconnect between implied and realised is the basis of the volatility risk premium and the reason that managing vega is more nuanced than simply "being right about how much the stock moves."
Vega measures how much an option price changes for a 1 percentage point change in implied volatility. A vega of 0.20 means the option gains $0.20 if implied vol rises by 1 point. It captures the option sensitivity to market expectations about future volatility, not to actual stock price movements.
Because volatility has more time to affect the outcome of a longer-dated option. A 1% change in implied vol shifts the distribution of possible terminal prices more meaningfully over 1 year than over 1 month. The mathematical relationship is vega proportional to the square root of time, so a 4x increase in maturity roughly doubles vega.
Yes. This is exactly what volatility traders do. Buy an ATM straddle (call + put) and you are long vega with approximately zero delta. If implied volatility rises, both the call and put gain value. If it falls, both lose value. The delta from the call and put roughly cancel out, leaving pure volatility exposure.
FinLingo covers vega and volatility trading in Level 3 — 13 units across Greeks and vol modules. Explore vega curves in The Lab. Level 1 is free.
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