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 hospital owner Community Health Systems (NYSE: CYH) fell 10% briefly this morning after the company changed its buyout offer for Tenet Healthcare (NYSE: THC).

So what: The previous offer for $5 cash and $1 of stock has been changed to an all cash deal, partly because Community Health's stock is worth much less than when the offer was made. Last week, Tenet accused Community Health of overbilling Medicare and private insurers, which sent its stock into a tailspin.

Now what: Community Health was basically forced into this move because of the allegations and a U.S. government subpoena into possible improper claims to Medicare and Medicaid. Community Health is obviously serious about completing the deal for Tenet, and the company may have a harder time fighting off the bid now. For now, I'm going to watch this battle play out since both stocks have been all over the place lately.

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