September Swoon Sends LINN Energy LLC Down 21.6% and LinnCo LLC Down 7.5%

What: September was another month to forget for investors in LINN Energy LLC and LinnCo LLC , as their values dropped again. Driving the sell-off was oil's drop of more than 8% for the month, as well as LINN Energy's getting kicked out of a well-known MLP index. Yet the companies didn't equally feel the impacts of those catalysts, despite their rather direct relationship.

So what: As has been the case since oil prices turned lower last year, LINN Energy's unit price seems to be pummeled any time oil prices fall, since its cash flow rises and falls, to some extent, with oil prices. That certainly was the case in September.

The other big catalyst fueling LINN's selloff was news that it was jettisoned from the Alerian MLP index. That index, which tracks the 50 largest MLPs, is one that a number of funds try to match. So when companies are dropped from the index, these funds drop the companies as well, leading to additional selling pressure.

Those catalysts aside, it was interesting to see how they had a much more direct impact on LINN Energy's units than LinnCo's stock.

LINE data by YCharts

That wide deviation came even though LinnCo's only assets are the units it owns in LINN. What happened here is that the premium LINN Energy used to trade at relative to LinnCo has evaporated, largely because both have suspended investor distributions, before which investors were willing to pay a premium to own LINN over LinnCo. However, with distributions suspended, the premium has evaporated so that nowLINN units and LinnCo shares are trading for virtually the same price.

Now what: September was another wild month for LINN Energy and LinnCo, as both fell again because of oil prices and index changes. While the impact wasn't felt equally last month, it should going forward, as both companies are expected to remain volatile until there's more clarity on the future of the oil market as well as LINN's ability to maintain its large debt load.

The article September Swoon Sends LINN Energy LLC Down 21.6% and LinnCo LLC Down 7.5% originally appeared on Fool.com.

Matt DiLallo owns shares of Linn Co, LLC and Linn Energy, LLC. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.