Bitcoin’s meteoric rise starting in late 2020 has made it increasingly difficult for naysayers to dismiss the highly volatile cryptocurrency out of hand. Since the mysterious Satoshi Nakamoto released a nine-page paper explaining the technology in 2009, the biggest players in finance, business and government have debated whether it’s the currency of the future, whether it’s a currency at all, a risky, unregulated asset, a gift to organized crime, or as Nouriel Roubini put it, “the mother of all bubbles.” See who the bulls are, who the bears are, and how some have changed their tune over the years.