This Article examines digitized securities (sometimes called smart securities or security tokens) and the ability of blockchain-enabled smart contracts to automate compliance with certain aspects of US federal securities laws, reducing a major barrier to secondary liquidity in private markets. It further provides a high-level overview of distributed ledger systems, including their potential benefits as compared to existing technologies, analyzes certain obstacles that must be overcome for this technology to gain widespread adoption, and considers which existing solutions are most likely to generate widespread adoption.