Cryptocurrencies have become an important asset class in the last several years. Why do they have value, and how should policy-makers respond to their presence? “The value of crypto-tokens depends on user adoption of the underlying platforms, making it more volatile.” analyzes why cryptocurrencies are both valuable and volatile, and how those features relate to user adoption of the underlying platforms. “Monetary Policy for a Bubbly World” shows that in a world with recurring asset bubbles, monetary policy has an important role to play in controlling the size of the bubbles. “Consumers as Financiers: Consumer Surplus, Crowdfunding, and Initial Coin Offerings” shows that crowdfunding allows entrepreneurs to extract some consumer surplus when a project is undertaken, and thereby expands the range of feasible projects in an economy. “Trading Costs and Informational Efficiency” highlights that reduced trading costs can reduce market efficiency in the short run, as it may well increase the fraction of uninformed traders thereby reducing informativeness of trades.