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 home-health service provider Gentiva Health Services (Nasdaq: GTIV) caught a cold and fell 10% today after an analyst downgrade.

So what: Analyst Whit Mayo at Robert W. Baird downgraded the whole sector today, including Gentiva, Almost Family (Nasdaq: AFAM), and LHC Group (Nasdaq: LHCG), sending all three lower. He believes expectations are too optimistic for the stocks in 2012 and that cuts to Medicare reimbursement rates will be greater than expected.

Now what: If Mayo is right, these stocks could be put under more pressure, so these developments should be watched closely. Gentiva is his favorite of the group, with the only neutral rating, and with a 10.6 P/E ratio, shares aren't terribly expensive if conditions worsen only slightly. I don't see today's drop as a buying opportunity. But if Mayo's predictions turn out to be wrong, and financial results are strong in coming quarters, these stocks are looking awfully cheap.

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