Michael Novogratz says cryptocurrencies could be worth north of $5 trillion in five years -- if the industry can come out of the shadows.

“The Nasdaq got to $5.4 trillion in 1999, why couldn’t it be as big?” the former hedge fund manager said in an interview, referring the Nasdaq Composite Index. “There’s so much human capital and real money being poured into the space and we’re at the takeoff point.”

To get there, though, companies need to develop sound business principles to satisfy regulators and lend legitimacy to the budding industry, one of Wall Street’s biggest bitcoin bulls said Tuesday at the CB Insights Future of Fintech conference in New York.