Target date funds, or TDFs, are an increasingly important part of the retirement investment universe. These funds are often thought of as holding a mix of debt and equity investments, with the equity proportion declining according to a predetermined glide path. In reality, current TDFs are far more complex. New regulations, such as the U.S. Department of Labor’s Fiduciary Rule, create uncertainties for TDFs going forward. Given these uncertainties and the sheer size of the TDF market, the current docket of TDF-related litigation is likely to grow.