Prospective underwriter means a person:
(1) Who has submitted a bid to the issuer or selling security holder, and who knows or is reasonably certain that such bid will be accepted, whether or not the terms and conditions of the underwriting have been agreed upon; or
(2) Who has reached, or is reasonably certain to reach, an understanding with the issuer or selling security holder, or managing underwriter that such person will become an underwriter, whether or not the terms and conditions of the underwriting have been agreed upon.
17 CFR § 242.100
Preliminary note: Any transaction or series of transactions, whether or not effected pursuant to the provisions of Regulation M ( 242.100-242.105 of this chapter), remain subject to the antifraud and antimanipulation provisions of the securities laws, including, without limitation, Section 17(a) of the Securities Act of 1933 [15 U.S.C. 77q(a)] and Sections 9, 10(b), and 15(c) of the Securities Exchange Act of 1934 [15 U.S.C. 78i, 78j(b), and 78o(c)].