The ETRACS Alerian MLP Index ETN Class B (AMUB) is a mutual fund that tracks the performance of the Alerian MLP Index, which includes the top energy infrastructure master limited partnerships (MLPs) in the United States. This fund offers investors exposure to the MLP sector, which typically generates stable cash flows and offers attractive yields. As a Class B ETN, this fund may have a lower expense ratio compared to other share classes, making it a cost-effective option for investors seeking exposure to the MLP market.