A formal written offer to sell securities to investors, which sets out relevant facts that the investor should have in order to make an informed purchasing decision. Under United States Securities Law such a prospectus must be approved by the SEC and must be accurate. If not the promoters of the company (i.e., the managers, bankers and lawyers) are subject to serious civil and criminal liability. The only exception to the prospectus requirement is a “private placement” under Regulation D, where shares are only sold to accredited investors. A prospectus is sometimes referred to as an SEC Form S-1.