After yesterday's 15% plummet, investors in Inside Value selection CarMax (NYSE:KMX) must feel as if they just drove off a cliff -- or want to. CarMax performed well in the quarter, but its results weren't as robust as it would have preferred. Furthermore, sensing a continued deceleration, it lowered its outlook for the full year, which sent the stock price careening over the edge.

In the second quarter, the company increased earnings 20% to $65 million, or $0.29 per share, matching expectations. Sales totaled $2.1 billion, just barely missing estimates, and certainly not worthy of the massive selloff. Even with the slowing growth, margins edged higher, and free cash flow improved by nearly 11%.

But CarMax loses control (and investors' confidence) in its discussion of full-year expectations. It lowered its earnings outlook to a range of $0.92 to $0.98 per share, from a previous estimate of $1.03 to $1.14 per share. Its updated guidance indicates flat to modest earnings growth of 6.5%.

Despite its disappointing performance in the first half of the year, and its expectations for the rest of the year, the company feels confident about its strategy, pointing to the overall economy as the reason for its lackluster performance. It will do its best to weather the tumultuous market without shiftomg its focus away from aggressive growth, and it will proceed with plans to expand its footprint by 15% to 20% annually.

I'd caution Fools not to play lemming and blindly follow the mass exodus. Instead, examine what drew you to invest in the company to begin with, and see if that's changed. I think you'll see that the characteristics that made CarMax sparkle remain. It maintains its firm grip as the industry's leader, and it's a company that competitors, including America's Car-Mart (NASDAQ:CRMT) and Penske Auto Group (NYSE:PAG), would no doubt love to emulate.

If you already own shares of the company, don't lose sight of your goals. For those with a little extra cash lying around, you may want to keep a close watch on CarMax. With its meager annual estimates, its forward P/E hovering around 17 isn't a screaming value. However, if it can accelerate growth, it should again be a great performer down the road.

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Fool contributor Mike Cianciolo holds no position in any of the companies in this article. CarMax is an Inside Value recommendation. The Motley Fool has a top-flight disclosure policy.