Doordash. Space X. Epic Games. These are all private US companies valued at more than a billion dollars—unicorns. Unicorn sightings, once rare, have become commonplace. As U.S. companies get bigger while staying private, a few questions become urgent: Who should be able to invest in these companies? Main Street investors? What protections should these investors have? Issues about access and investor protection are on the table at the SEC, where seemingly technical rule changes are really a fight over access and information in the new world of unicorn investments.