Every broker or dealer conducting a general securities business registered with the Securities and Exchange Commission (Commission) must comply with SEC Rule 15c3-1, the Net Capital Rule. The Net Capital Rule is designed to ensure that broker-dealers will have adequate liquid assets to meet their obligations to investors and liabilities to other creditors. The rule is complex and specifically addresses the liquidity, market, and counterparty credit risks associated with the proprietary positions of the broker-dealer. In the May 1992 edition of The Business Lawyer the author published an overview of the rule entitled “The Net Capital Rule,” which concluded by observing that the Commission needed to update the rule to take into account the growth in derivative instruments. Since then the Commission has made multiple amendments to the rule that do just that, culminating with the recent amendments governing swap transactions mandated by Dodd-Frank. This article updates the 1992 article by taking the reader through those rule changes, including the Commission’s evolutionary recognition of quantitative models to measure the risk associated with derivative positions.