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 OraSure Technologies (NASDAQ:OSUR), a manufacturer of oral fluid diagnostic products, was chewed up and spit out by investors, sending shares lower by as much as 15% following its fourth-quarter earnings results and 2013 forecast.

So what: Investors don't seem to care too much about what OraSure's done for them lately so much as what it'll do for them in the future. For the fourth quarter, OraSure reported a 6.5% decrease in sales to $22.1 million and a loss of $0.11 per share. Both figures surpassed expectations that called for a loss of $0.14 on revenue of $20.9 million. However, the company's first-quarter guidance missed the mark badly. OraSure anticipates reporting sales of $20 million to $21 million and a loss of $0.18-$0.19, compared to the $23.1 million in sales and $0.12 loss the Street was expecting. OraSure made sure to remind investors that the first quarter is typically its slowest, but couldn't hide the fact that infectious disease test sales will be down.

Now what: Yet again, we have another example of a company whose sales are generally moving in the correct direction, but it can't seem to turn that elusive profit -- and it probably won't until Europe or the U.S.'s economy improves, either! OraSure has had a knack over the past year of easily surpassing estimates when it's time to report, but it's having trouble providing guidance that investors can wrap their hands around. This is a company I'd put on the backburner of your watchlist until it shows that it can be consistently profitable.

Craving more input? Start by adding OraSure to your free and personalized watchlist so you can keep up on the latest news with the company.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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