Any of the alternative methods for companies looking to become public without an underwriter.  There are other methods of going public other than an initial public offering (IPO), including reverse mergers, self-filings, Rule 504 offerings, and Regulation A offerings; however, the most popular alternative public offerings are reverse mergers with shell companies (Form 10 shells) and special purpose acquisition companies (SPACs). Private companies, having limited access to the capital markets, resort to alternative ways to go public. In a reverse merger, a private company mergers with a public company that typically has no assets or liabilities (i.e., a shell company). The resulting publicly traded company is known as a public shell since its corporate structure is the only element it has as a company.

An alternative public offering is usually viewed as the combination of a reverse merger with a simultaneous private investment of public equity (PIPE).

Not all alternatives necessarily include traditional public offerings. Characteristically, alternative public offerings provide a viable means to raise capital and are considerably quicker and less expensive than a typical initial public offering.

Alternative public offerings are also referred to as direct public offerings (or in specific cases as investment crowdfunding).