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 operator Tenet Healthcare (NYSE: THC) soared a staggering 55% in intraday trading Friday on news that larger rival Community Health Systems (NYSE: CYH) offered to buy it for $3.3 billion in November.

So what: The deal, which would create the nation's largest hospital operator if accepted, represents a whopping 40% premium to Tenet's closing price Thursday. Of course, with Tenet having rejected the unsolicited bid as "not remotely fair value," Mr. Market feels confident enough in a substantially higher offer to send the shares well past the offer price. 

Now what: When you make 50% in one morning, taking at least some dough off the table seems like the prudent thing to do. While it might be tempting to hold out for a higher offer, the risk (even if it's small) that Community Health might back off altogether might not be worth taking. With Tenet peers like LifePoint Hospitals (Nasdaq: LPNT) and Health Management (NYSE: HMA) both trading at reasonable price multiples, there might be cheaper places to place your bet.

Interested in more info on Tenet? Add it to your watchlist.

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Fool's disclosure policy always gets a perfect score.