Image source: HollyFrontier. 

What: Shares of HollyFrontier (HFC) are up close to 10% as of 2:30 p.m. today following the company's earnings release, in which it posted an improvement over the same quarter last year.

So what: Despite a loss of $0.24 per share, most of it was attributed to a non-cash writedown of its inventories. If we were to strip out these writedowns, earnings per share would have been $0.24 per share compared to last year's adjusted fourth-quarter result of $0.12 per share.

Investors seemed to like the strong operational results that accompanied those earnings. HollyFrontier's gross margin per barrel increased to $9.91 across all its refineries as it increased its use of cheaper heavy crudes as feedstocks and improved its gasoline yields. At the same time, management noted that it had repurchased $261 million in stock in the fourth quarter as part of its accelerated share repurchase program. 

Now what: Refining margins will come and go for HollyFrontier and its peers, so it's the little things that matter. Increasing its ability to source cheaper feedstocks and orienting its refineries to produce higher percentages of high-value products like gasoline is a step that any investor wants to see because it shows HollyFrontier isn't just sitting on its laurels and relying on refining margins to make its life easier.

With shares down 20% over the past year, perhaps today's earnings results were a wake-up call to investors that HollyFrontier is doing rather well.