A blackout period refers to a period of time when user access or some type of activity is denied. The term has several possible meanings, depending on the context. They are as follows:
Public company. The blackout period is a number of days prior to the official release of earnings information by a public company, when certain directors, officers, and other employees cannot trade the company's stock.
Retirement plans. The blackout period is a number of days during which employees are not allowed to make changes to their employer-sponsored retirement plans. The reason for this stoppage is that the plan is being revised or shifted to a different brokerage during the blackout period.
Stock options. The blackout period is a number of days during which the holder of a stock option is not allowed to exercise it.