I combine survey and transaction data to empirically characterize secondary markets for wholly owned businesses in the United States. While markets are active, with an estimated 2.9% of businesses sold annually, they are also frictional, with the median sale taking between 170 and 200 days. To quantify the impact of market frictions on business formation, ownership, continuation, and entrepreneurial welfare, I estimate a search and matching model of business ownership and resale using novel data from an online market. In the estimated model, removing secondary markets reduces output by almost 21%, while firm entry rates rise by 2.5 percentage points, highlighting a trade-off between firm entry and continuation that is absent in models without resale. I then characterize the planner's problem and show that buying and selling decisions will generally never be simultaneously efficient. A transaction tax used to finance a minimum income scheme for entrepreneurs raises welfare by 0.94%. Finally, I extend the model to include founding risk and find the risky economy is five times more responsive to frictions relative to the benchmark economy.