This isn't going to move like a stock from this point forward, it's priced based on yield, and it's already near the top in the midcap space (although, granted, LINE is the monster of the group). If there's further yield compression in the MLP's it could move up a bit more without any fundamentals changing, but really I would expect the MLP's to max out around this point until there's a future distribution increase, and I think you're seeing that in LINE over the past couple months.
There's an article on a tech analysis of LGCY today, and I just had to laugh. A cash flow stock priced on yield in a group of peers with similar yields is not going to respond to chart signals, past some arbitrary witchcraft level and suddenly go on a tear. These things don't trade like that, the story has been yield compression that's now flattening out. Chart LINE with MWE, NGLS, LGCY and EVEP, they're clones over the part three months, random walk jags aside. Note also how the larger MLP's have appreciated the most (that is, they trade at a lower yield). Just what you'd expect.