Of all the "asset " classes, Bitcoin has had an unfathomable year, rising 160% and smashing all-time records along the way. We go behind the cryptocurrency's momentum with Michael Sonnenshein of Grayscale Investments to see who's buying Bitcoin, and what the future looks like. The unicorns have returned for winter as Doordash and AirBnB are set to make their public debuts at fantasy-level valuations. What investors need to know about the IPO party at the end of the year. And why Modern Monetary Theory is the term of the week, and what you need to know about it. All that and more on the Investopedia Express with Caleb Silver.