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 Bio-Reference Laboratories (NASDAQ:BRLI), a provider of clinical laboratory testing services, slumped as much as 22% after reporting its preliminary fourth-quarter results and fiscal 2014 full-year guidance.

So what: According to Bio-Reference's press release, the company now anticipates reporting revenue of approximately $192 million on $0.40 in EPS in the fourth quarter. By comparison, Wall Street expected only $189 million in sales, but a significantly higher profit per share of $0.55. The company attributed the downward pressure on its profits to weakness in reimbursement rates due to the rollout of Obamacare, as well as the 16-day government shutdown. Bio-Reference did note that demand has remained strong, but that reimbursement rates simply weren't working in their favor. The company also released guidance for fiscal 2014, which includes a projected gain in sales and net income of 10% -- both also well below the Street's expectations.

Now what: I can't emphasize enough that I really do like laboratory testing companies to benefit over the long run, especially as the baby boomer population ages, and select diseases begin to benefit from the adoption of personalized treatments aided by genetic testing. However, over the near term, laboratory testing companies like Bio-Reference are built to suffer, with Medicare reimbursements rates seeing some relatively steady declines in accordance with the passing of the Patient Protection and Affordable Care Act. Unless we see a major spike in demand, today's move lower may very well be warranted.

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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