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 Sonic Automotive Inc. (NYSE:SAH) were decelerating today, falling as much as 10% after the car dealership posted second-quarter results this morning.

So what: Sonic delivered revenue growth of 6.8% to $2.35 billion, short of $2.38 billion, while on the bottom line, earnings per share came at $0.51, missing expectations at $0.53. Company President B. Scott Smith called the performance in the quarter "solid," and said the One-Sonic-One Experience initiative, designed to bring a revolutionary shopping and buying experience to the customer, and the pre-owned-vehicle initiative, which is the product of a proprietary inventory management system that helps drive used vehicle sales, should boost growth in the second half of the year. 

Now what: Sonic stock mostly recovered throughout the session, trading just 4% toward close as some bullish options buying seemed to lift shares. Considering the earnings miss was mild, a 10% sell-off seems exaggerated. Auto dealerships are also heavily influenced by macroeconomics, and with car sales continuing to grow after a long lull, Sonic figures to benefit. For long-term investors, there seems to be little reason to adjust your investment thesis based on today's report.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.