Elon Musk recently tweeted that he intends to take Tesla private, that is, to take Tesla off U.S. stock exchanges. In a parallel development, the number of companies listed on U.S. stock exchanges has declined by almost 50% from its peak in 1996, despite dramatic increase in aggregate market capitalization. Many conjectures have been offered to explain this controversial trend. We offer a new explanation: the rising role of digital firms in the U.S. economy.