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 tha…