It’s been a roller coaster of a ride for the energy markets. MLPs saw nothing but upward momentum during the first half of 2014, as the Alerian MLP Infrastructure Index (AMZI) rose 12.5% on a price return basis through June 30. The index reached an all-time high of 890.66 (+16.4%) on Aug. 29, only to retract all of the year’s gains by Oct. 14. It recovered shortly thereafter and through Nov. 28, the AMZI was up 7.1% for the year.

In mid-March, the Interstate Natural Gas Association of America updated and expanded its capital spending report, estimating the need for $641 billion of natural gas, crude and NGL infrastructure spending through 2035. This new number is $390 billion higher than the organization’s 2011 estimate. Several companies have noted that North America is undergoing a major repiping in describing the construction of new and repurposing of existing midstream assets to accommodate new and growing supply areas.

In 2014, many pipeline reversal and/or conversion projects were announced, and the industry even saw a revival in natural gas pipeline projects. Overlaid with increased international demand for cheaper energy resources, the stage is set for more gas and ethane export projects.

Mergers and acquisitions and restructuring mania took over a large part of 2014: Williams Partners and Access Midstream Partners announced a merger, Targa Resources announced the acquisition of Atlas’ midstream assets, Regency Energy Partners LP bought PVR Partners and Enterprise Products Partners LP acquired the general partner of Oiltanking Partners LP.

And who could forget the Kinder Morgan family simplification?

Starting in June and lasting through press time, crude prices plummeted. MLP unit prices were relatively unaffected by the pullback until October. However, the first two weeks of October and the four trading days following Thanksgiving were among the most volatile times of the year for MLPs. Investors who feared catching a falling knife took the opportunity to do some early tax loss harvesting, while longer-term investors used the selloffs to add to positions in defensive names, which tend to be larger, investment grade, and with less direct sensitivity to commodity prices.

Going into 2014, everything was rosy for the booming energy markets. But entering 2015, many questions remained unanswered: Just how low will oil prices go? How long do commodity prices need to stay below breakeven before production pulls back? Where are interest rates going? What other businesses will enter the MLP structure?

Remain seated, keep your hands in and make sure your restraints are in position, because the ride isn’t over yet.

Maria Halmo and Emily Hsieh, CPA, are directors for Alerian, an independent provider of MLP and energy infrastructure market intelligence. Over $20 billion is directly tied to the Alerian Index Series. For more information, please visit www.alerian.com/alerian-insights.