Earnings season hit its crescendo this week, leading to a lot of volatility. But it wasn't just the earnings reports that sent several energy stocks down. Instead, what really burned investors was the outlook these companies gave when it came to the future of shareholder distributions. Topping this list of biggest losers, according to S&P Capital IQ data, were Atlas Resource Partners (UNKNOWN:ARP.DL), Memorial Production Partners (NASDAQ:MEMP), and Plains GP Holdings (NYSE:PAGP).

Atlas Resource Partners move last week was interesting to say the least as its plunge was initially fueled by disappointing news from peers, including Memorial Production Partners. That news from Memorial Production Partners, which included a massive distribution cut, fueled concerns that Atlas Resource Partners would follow suit when it reported second-quarter results. A cut, however, wasn't in the cards, which is why the stock recovered some, but not all, of its losses in early trading on Friday. 

Plains GP Holdings' plunge was also related to its distribution though the company merely gave a warning that growth might slow instead of actually making a cut. That being said, income investors bailed on the warning as concerns grow over the future of Plains GP Holding as its MLP Plains All American Pipeline (NYSE:PAA) is struggling. Those struggles, which include a recent oil spill and weakness due to low oil prices, are really spilling over into Plains All American Pipeline's results. 

To learn more about why these catalysts caused the stocks to plunge so sharply this week, check out the following slideshow.