Lesson 4 of 5

Gamma & Vega (Brief, Practical)

Gamma -- The Rate of Change of Delta

Gamma measures how fast delta changes for each $1 move in the stock. If delta is your speedometer, gamma is your acceleration gauge. For option sellers, gamma is a risk to manage: high gamma means delta can shift quickly, turning a comfortable OTM position into an ITM one in a hurry.

Gamma

Gamma = Change in Delta / $1 Change in Stock Price | Highest for ATM options near expiration

Gamma is highest for at-the-money options and increases as expiration approaches. This is why the final days before expiration can feel volatile for premium sellers -- small stock moves create large swings in the value of your position. Selling with 30-45 DTE and closing early helps you avoid this 'gamma risk' zone.

Gamma Risk for Sellers

When you are short options, you are short gamma. This means a sudden move against you accelerates your losses because delta is growing against you. This is the core argument for not holding short options into the final week -- gamma is highest exactly when you have the least time to recover.

Vega -- Sensitivity to Volatility Changes

Vega measures how much an option's price changes for each 1-percentage-point change in implied volatility. If IV rises by 1%, a put with a vega of 0.10 gains $0.10 per share ($10 per contract). As a premium seller, you are short vega -- you benefit when IV falls and are hurt when IV rises.

Vega

Vega = Change in Option Price / 1% Change in IV | Highest for ATM, longer-dated options

Vega and Trade Timing

Because you are short vega when selling puts, your ideal scenario is to sell when IV is high and profit as it contracts. This is why IV Rank matters: entering trades at elevated IV gives you a vega tailwind on top of theta decay.

Gamma (Key Points)

+Measures delta's rate of change
+Highest for ATM options near expiration
+Short gamma = risk of accelerating losses
+Manage by closing before final week

Vega (Key Points)

–Measures sensitivity to IV changes
–Highest for ATM, longer-dated options
–Short vega = benefit from IV contraction
–Manage by entering when IV is elevated

Key Takeaways

•Gamma measures how quickly delta changes -- short sellers face gamma risk near expiration.
•Vega measures sensitivity to IV changes -- premium sellers benefit from IV contraction.
•Managing gamma and vega boils down to smart timing: sell at 30-45 DTE with elevated IV, close early.

Quick Check

1/2

When is gamma highest for an option?

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