The document is a report from PitchBook on unicorns (privately held startups valued at $1 billion or more). It discusses the rising number of unicorns in recent years and analyzes financing terms of unicorn rounds. Key points include: the number of US unicorns nearly doubled in 2015; recent rounds have focused on strong downside protections for investors through minimum IPO valuations, liquidation preferences, and anti-dilution provisions rather than high upside; protections have increased after some companies went public at prices below late-stage private valuations.