Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What's happening: Shares of Darling Ingredients (NYSE:DAR) were up 12% as of 11 a.m. Friday after the rendering and biodiesel specialist announced encouraging first-quarter results.

Quarterly revenue fell 8.2% year over year to $874.7 million. That resulted in a 20.3% decline in adjusted earnings before interest, taxes, depreciation, and amortization to $103.5 million, and 59.1% lower adjusted earnings of $0.09 per diluted share. But analysts, on average, were expecting Darling Ingredients to achieve adjusted earnings of just $0.07 per share on higher revenue of $900.3 million.

Darling's results included a 6.6% decline in revenue from its Feed Ingredients business to $547.5 million, and a 5.6% decline in the segment's operating income to $35.4 million. In both cases, lower fat and corn prices as well as currency headwinds were to blame. Meanwhile, revenue from Food Ingredients fell 7.9% to $270.2 million, hurt by the ongoing closure of the Russian trade border, and partially offset by higher volumes, strong demand from its gelatin business, and higher demand and lower raw materials prices in China. 

Finally, excluding Darling's Diamond Green Diesel joint venture with Valero, Fuel Ingredients net sales fell 14.5% year over year to $57 million, while operating income increased by $0.2 million to $2.5 million. Diamond Green Diesel, for its part turned in a quarterly loss of $2.2 million amid lower RIN values given today's "uncertain regulatory environment" surrounding renewable volume obligation requirements this year.

Why it's happening: This all might sound bad, but investors should remember these headwinds mostly carried over from last quarter, when Darling beat expectations primarily because of the reinstatement of the biodiesel blender's tax credit. Once again, Darling CEO Randall Stuewe expressed confidence that, despite Congress' inaction so far in 2015, the blender's tax credit should again be reinstated and retroactively applied later this year.

With respect to Darling's other businesses, Stuewe elaborated, "On a sequential basis, we have executed on a number of changes to improve operating performance in light of lower grain, protein and fat prices worldwide flowing through our business segments. We continue to focus on margin management, operating efficiencies and reduced administrative costs to offset the headwinds."

These headwinds shouldn't last forever, and Darling is doing an admirable job making the most of its current situation. In the end Darling Ingredients should emerge a stronger business for it, so it's no surprise the market is bidding up the stock today.