Abby Woodham, a Morningstar analyst, recommends JPMorgan Alerian MLP Index, which yields 4.9%. Since it was launched in 2009, the ETN has grown to $4.8 billion in assets, ranking as the largest entrant in the field. Because of its size and popularity, the ETN is liquid and easy to trade, she says. Woodham says the JPMorgan investment does come with some special risks because it is an ETN. With a traditional mutual fund or ETF, investors own a stake in a pool of assets. But investors in an ETN only receive a pledge from the manager to provide returns equal to an index. In this case, the returns will approximate the Alerian MLP Index, minus an expense ratio of 0.85%. If JP Morgan goes bankrupt, then investors could receive nothing. Woodham argues that the ETN is a solid bet. "Because you are dealing with JPMorgan, the risk of default is minimal," she says. Investors who worry about depending on the credit of a single bank may prefer the ALPs Alerian ETF, which yields 6.0% and has $4.3 billion in assets. During the financial crisis, MLP share prices sank, and the yields spiked to more than 16%. Since then prices have rallied and the yields have declined. Jeremy Held of ALPS argues that the prices are at fair values as indicated by yields. "Historically the yields have averaged 6% to 7%, and we are right in that range now," he says. Follow @StanLuxenbergThis article is commentary by an independent contributor, separate from TheStreet's regular news coverage.