Brokers and investment advisors have duties under the law to know their customers' investment needs and tolerance for risk. Often when investors lose money, they consider whether investments made by their advisor or recommendations made by their broker were appropriate. For more than two decades, our economists have been called upon to render opinions in disputes between investors and their broker-dealers, investment advisors, and fund managers. NERA experts have provided analyses supporting investors and brokers for use in arbitration and the courtroom. Our work has focused both on liability, examining allegations such as unsuitability and churning, and damages, measuring how much investors might have earned under an alternative investment strategy. Our expertise with financial theory and experience with various trading strategies and instruments allows us to put ourselves in the shoes of parties while the investment decisions were being made in order to better focus on whether the trading practices at issue were appropriate.