A quiet period is a measure of time during which corporate insiders are restricted from disclosing information relative to the performance or prospective performance of a company before that information is made public.
Quiet periods are mandated in conjunction with initial public offerings (IPOs), earnings seasons and other events that have significance for investors. The purpose of the quiet period is to ensure that no one with inside information can selectively disclose it to give particular investors an unfair advantage. Buying and selling securities based on non-public information, known as insider trading, is illegal.
Quiet periods for fiscal quarters and fiscal years commence on the day after the close of the quarter or year and end after financial results have been made public. Quiet periods are also known as "waiting periods." The term is sometimes confused with blackout period, a period of time during which corporate insiders are legally restricted from trading if they are in possession of relevant information that has not yet been made public.