CORRECTION! That is in my earlier post and my apologies. The short MLP index symbol is MLPS and not MLPI. MLPI is the infrastructer mlp index (AMZI). The short product is 1x the mlp index and has not traded any shares today although there is a bid and ask. Enterprise and Kinder Morgan are the 2 big components in here. Im sorry for the mix up.

Here is a link to the Alerian page describing it and from there you can link to their other products.