This document provides an overview of a presentation exploring the physical properties of regulatory ecosystems using securities filings data. It is divided into three parts. Part I discusses using 10-K filings as a data source to gain insights into legal complexity and uncertainty. Part II measures the "temperature" and diversity of the U.S. regulatory ecosystem over time based on references to acts and agencies in filings. Part III examines regulatory dynamics and potential microclimates by analyzing networks of similarities between companies' regulatory exposures. The goal is to better understand sources of legal complexity, uncertainty, and risk through empirical analysis of large-scale public data.