Special purpose acquisition companies, or SPACs, have been around in various forms for decades, but during the past two years they''ve taken off in the United States. In 2019, 59 were created, with $13 billion invested; in 2020, 247 were created, with $80 billion invested; and in the first quarter of 2021 alone, 295 were created, with $96 billion invested. In 2020, SPACs accounted for more than 50% of new publicly listed U.S. companies. SPACs are publicly traded corporations formed with the sole purpose of effecting a merger with a privately held business to enable it to go public. Compared with traditional IPOs, SPACs often offer targets higher valuations, greater speed to capital, lower fees, and fewer regulatory demands. Despite the investor euphoria, however, not all SPACs will find high-performing targets, and some will fail. Many investors will lose money. As an investment option they have improved dramatically, especially over the past year, but the market remains volatile. More changes are sure to come, which means that sponsors, investors, and targets must keep informed and vigilant. This article is not a blanket endorsement of SPACs. It is simply a guide for businesspeople considering a move into this rapidly evolving (and for many, unfamiliar) territory.