All offers and sales of securities must be registered under Section 5 of the Securities Act of 1933, or covered by an available Exemption. The SEC takes a broad view as to what is an "offer," so any kind of "market conditioning," i.e., something that makes you want to make an investment, is considered an "offer" of securities. Companies need to file a registration statement with the SEC before selling shares to the general public, i.e. an Initial Public Offering. There are exemptions available, typically for accredited investors or qualified institutional buyers, and the new crowdfunding exemption as provided under the CROWDFUND Act.