What: December was a tough month for Pioneer Natural Resources (PXD) investors after two events caused the stock to fall by double digits. That said, December wasn't all bad news, with the company having one positive story that's also worth pointing out.

So what: The main catalyst for the December slide was the price of crude oil, which continued to weaken, ending down 11% for the month to just over $37 per barrel. That price is well below what Pioneer needs in order to earn lucrative drilling returns, with the company's current drilling program banking on a slightly more than $50 oil price for 2016 in order to deliver a 50% to 60% per well drilling return. With oil well below that level, drilling returns will suffer.  

The other factor weighing on Pioneer Natural Resources' stock last month was word from its credit rating agency that it has been put on review for a potential credit rating downgrade. Pioneer was far from the only oil company put on review; it's just one of 29 U.S. independents given notice, joining fellow Permian Basin-focused peer Concho Resources (NYSE: CXO). That review aside, both companies have very low leverage levels, including sub-2.0 times debt-to-EBITDA ratios. Furthermore, Pioneer Natural Resources' overall debt picture is the better of the two, and is one of the best in the entire energy sector. 

PXD Debt To Capital (Quarterly) Chart

PXD Debt To Capital (Quarterly) data by YCharts.

On an even more positive note, Concho Resources and Pioneer Natural Resources were named as JPMorgan's top large-cap picks among E&P companies focused in the Permian earlier last month. The bank praised Concho's "deep inventory of high return well locations in the Delaware Basin" while also noting that Pioneer should begin to realize a positive turn in capital efficiency to go along with oil growth, which should drive future outperformance. While the two other concerns outweighed this bold call, it does give long-term investors something positive to look forward to in the future. 

Now what: While December was a tough month for Pioneer Natural Resources, the company is better positioned than a lot of other oil companies. It has low leverage and a very low-cost oil position, which should drive strong future results even if oil prices remain weak. Furthermore, if oil does rebound, Pioneer is well positioned to capture all that upside has to offer.