Expiration
The date an option stops trading and its rights end. After expiration, an unexercised option no longer exists.
Standard U.S. equity options expire on the third Friday of the month, and many underlyings also list weekly expirations, with some index products listing one every trading day. Options that finish at least $0.01 in the money are generally exercised automatically under OCC rules unless the holder instructs otherwise, and the rest expire worthless.
As expiration approaches, the time value in an option shrinks and a near-the-money option’s price becomes more sensitive to moves in the underlying. Days to expiration, often written DTE, is the count of days left.
Illustrative example (hypothetical numbers, not a real trade): a call bought 30 days before expiration for $2.00 is a 30 DTE contract. If the underlying does not move, the time value in that $2.00 declines over those 30 days, and on expiration day only the intrinsic value is left.