The number of initial public offerings (IPOs) in the United States has been much lower since 2000 than in the preceding two decades, although there was a surge in IPO activity in 2021. The Securities and Exchange Commission (SEC) has attempted to reduce the regulatory and cost burdens of going public. Important new developments in the U.S. IPO market include confidential filings, testing the waters, direct listings, and special purpose acquisition companies (SPACs). Related research sheds light on whether the new developments can help capital formation and lower the costs of going public. Also relevant are the motives for going public, new insights into IPO pricing, institutional investors’ pre-IPO investments, and the consequences of firms’ IPO decisions. In the U.S., the majority of IPOs have used the bookbuilding mechanism, which involves generating and recording investors’ buying interests. Different companies prefer different mechanisms for going public. Bookbuilding is valuable for companies that face uncertainty regarding investor demand. A private firm may prefer selling itself to a publicly traded acquiring firm over an IPO in order to expand more quickly by utilizing the acquirer’s capital and established platform. A high-growth firm may prefer a merger with a SPAC over a traditional bookbuilt IPO due to the ability to use solid forecasts to increase the stock’s valuation. And companies with strong brand recognition or easy-to-understand business models, but no immediate cash needs, may find a direct listing more attractive, especially when their insiders have large diversification or liquidity needs. The SEC and other regulatory agencies should embrace and enhance these alternative mechanisms. Economies-of-scope considerations, globalization, regulatory and disclosure requirements, and the relative costs of public versus private capital all play a part in firms’ decisions to go public. Careful examinations of the benefits and costs are still needed. Possible widespread use of confidential filings and testing-the-waters communications after the regulatory changes initiated by the 2012 JOBS Act can substantially influence information production, IPO decisions, and IPO pricing. Private companies have increasingly used direct listings and SPAC mergers to go public, and emerging evidence suggests these methods will continue to evolve. Several recent papers have examined IPO underpricing across countries, and their findings are consistent with both information-asymmetry-based explanations and those based on issuer–underwriter conflicts. Information asymmetry helps explain the 7% average IPO underpricing in the U.S. during the 1980s. However, explanations based on agency problems, underwriter power, and issuer complacency are instructive for understanding the average underpricing of over 18% for all IPOs since then or over 50% for large subsets that can be identified ex ante. Future research would be useful to shed light on the predictability and magnitude of IPO underpricing, as well as on the effects of regulations and issuer–underwriter conflicts on underpricing. Recent research shows that IPOs have far-reaching effects. They not only influence the financing and investment policies of the issuing companies, but also have spillover effects to other companies, local communities, and labor markets.