Lesson 5 of 5

How Greeks Change as Expiration Approaches

The Expiration Effect on Greeks

As expiration draws near, every Greek shifts in ways that matter to premium sellers. Understanding these shifts is what separates disciplined wheel traders from those who get caught by surprise. The final 7-10 days before expiration are when the Greeks behave most dramatically.

Delta Near Expiration

With little time left, delta becomes binary. OTM options see their delta collapse toward 0, while ITM options see delta approach -1.0 (for puts). Options near the strike price become very sensitive -- a small stock move can flip them from OTM to ITM. This is directly caused by elevated gamma.

Theta Near Expiration

Theta reaches its peak in the final days. An option that decayed $3/day at 30 DTE might be decaying $8-10/day at 5 DTE. This sounds great for sellers, but the catch is that you are only capturing small remaining premium while exposed to maximum gamma risk. The risk/reward ratio shifts unfavorably.

Theta acceleration

Theta ~ Premium / sqrt(DTE) | As DTE shrinks, daily decay per dollar of remaining premium increases dramatically

Gamma Near Expiration

Gamma spikes for near-the-money options as expiration approaches. This makes your position extremely sensitive to stock moves. A $1 stock move that would have changed your P&L by $20 at 30 DTE might change it by $60 at 2 DTE. This is the primary reason professional sellers close or roll before the final week.

Vega Near Expiration

Vega decreases as expiration approaches. With so little time left, changes in implied volatility have a smaller effect on the option's price. This means IV shifts in the final days matter less than delta and gamma shifts. Your focus should shift from IV to managing gamma exposure.

The Practical Playbook

Sell at 30-45 DTE when theta is beginning to steepen and gamma is low. Close at 50% profit or at 14-21 DTE, whichever comes first. Roll to the next cycle if needed. This keeps you in the 'theta-friendly, gamma-safe' zone continuously.

Delta: becomes binary (0 or 1) near expiration; high assignment uncertainty near the strike.
Theta: peaks in the final days but premium remaining is thin.
Gamma: spikes for ATM options, making positions very sensitive to stock moves.
Vega: shrinks to near zero as IV changes have minimal impact with little time left.

Near-Expiration Scenario

You sold a 30-DTE put at the $95 strike for $2.00 when the stock was at $100. With 3 DTE, the stock is at $95.50 and the put is worth $0.80. Delta is -0.45, gamma is 0.12, and theta is -0.15. A $1 drop in the stock could push delta to -0.57 and the put to nearly $1.40. Closing now locks in $1.20 profit (60% of max) and eliminates the risk of a last-minute assignment.

Key Takeaways

•Near expiration, delta becomes binary, theta peaks, gamma spikes, and vega shrinks.
•The risk/reward of holding through the final week is unfavorable for premium sellers.
•Close positions at 50% profit or before 14 DTE to stay in the optimal theta/gamma zone.
•Roll to a new cycle rather than sweating out the last few days of a trade.

Quick Check

1/3

Which Greek poses the greatest risk to premium sellers in the final week before expiration?

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