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: Shares of Quad/Graphics (NYSE:QUAD) finished down 19% after disappointing investors in its third-quarter report last night.

So what: The print-products provider missed on both the top and bottom lines. Earnings per share of $0.64 were way short of estimates at $0.92, while revenue improved 20% to $1.2 billion, below the consensus at $1.32 billion. CEO Joel Quadracci said, "Results were adversely affected by ongoing industry pressures, economic and political challenges in Latin America, and a slower-than-expected turnaround in the underlying Vertis business."

Now what: In spite of the poor results, Quad/Graphics maintained its recurring free cash flow guidance of $360 million, and Quadracci said the Vertis integration was going well. Still, the company's full-year revenue guidance of $4.8 billion was below expectations of $4.99 billion. Management insists that free cash flow will allow it to invest in the business and "pursue opportunities that will drive future value." However, with flat growth expected next year, I'd be concerned about the poor guidance, which could be a red flag.