OCC automatically releases securities deposited with it to cover margin requirements on an option contract when the option contract expires. The securities are then allocated to your general free account. Notification of the released securities is received via the Collateral Loan Services functionality in the Settlement User Interface or automated output.
Note- OCC will begin releasing expired options at the close of business on the Friday following the expiration weekend. On the following Monday, OCC will release the deposits on expired options to DTC.