4.2.6.1. Regulation M, Rule 101, and Rule 102—Purchasing During Restricted Periods
Rule 101 forbids underwriters and their affiliates from purchasing or inducing someone else to purchase a covered security during a restricted period in connection with a public offering. Rule 102 prohibits this activity by issuers and their affiliates.
A covered security is any security that is governed by federal regulations or describes any security authorized to be listed on an exchange. A restricted period is the period beginning up to five days prior to the pricing of a new issue and ending once the public offering is completed. Regulation M applies principally to new issues of securities that are already being traded in the secondary market.
Restricted periods vary depending on the size and trading activity of the security.