There are many rules and laws that are relevant to share buybacks. For share repurchases that are not tender offers, the two most commonly referred rules for public companies in the United States are Rule 10b-18 and Rule 10b5-1 under the Securities Exchange Act of 1934 as amended (Exchange Act). As mentioned above, these rules are “safe harbors” that provide guidelines to reduce potential liability under US securities laws when their requirements are met.
Rule 10b-18 is non-exclusive, providing a safe harbor to issuers and certain of its affiliated purchasers from liability under certain market manipulation rules and Rule 10b-5 under the Exchange Act (when repurchases of the issuer’s common stock satisfy the Rule’s conditions as to when, where, and how share repurchases can occur).