Options Greeks
How does extrinsic premium compression alter your net Theta exposure on a day-to-day basis?
By Easy Money Scanner · Educational reference · Not investment advice
The short answer
As extrinsic premium compresses, often from falling implied volatility or approaching expiration, the dollar amount of theta decay changes daily since theta is calculated from the remaining time value itself.
How it works
Falling extrinsic value generally reduces the absolute theta figure since there is less time premium left to decay, though the percentage rate of decay relative to remaining value can still rise.
An example
After an IV crush following earnings, an option's theta may drop from -0.08 to -0.03 simply because much less extrinsic value remains to be eroded going forward.
Risk & limitations
Monitoring only theta in isolation can be misleading since compressed premium interacts with gamma and vega simultaneously, so review all Greeks together when assessing a position.
Examples are hypothetical, not trade recommendations. US contract and regulatory references do not automatically apply in Canada. Rules, margin requirements and broker policies can change; confirm them with the relevant authority and your broker.