The US entrepreneurial finance market has changed dramatically over the last two decades. Entrepreneurs who raise their first round of venture capital retain 30% more equity in their firm and are more likely to control their board of directors. Late-stage start-ups are raising larger amounts of capital in the private markets from a growing pool of traditional and new investors. These private market changes have coincided with a sharp decline in the number of firms going public—and when firms do go public, they are older and have raised more private capital. To understand these facts, we provide a systematic description of the differences between private and public firms. Next, we review several regulatory, technological, and competitive changes affecting both start-ups and investors that help explain how the trade-offs between going public and staying private have changed. We conclude by listing several open research questions.