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 diagnostic-test maker Gen-Probe (Nasdaq: GPRO) rocketed up today, gaining as much as 20% in intraday trading on heavier-than-average volume.

So what: Bloomberg reported today that Gen-Probe has hired investment bank Morgan Stanley (NYSE: MS) to manage a sale process and noted that bids are expected in the next couple of weeks. The article suggested that Novartis (NYSE: NVS), Thermo Fisher Scientific (NYSE: TMO), Danaher (NYSE: DHR), and Life Technologies (Nasdaq: LIFE) could be among the bidders.

Now what: As I noted yesterday with InterMune, this kind of news tends to get traders and short-term investors very excited. However, speculation on potential buyouts can often end in disappointment if nothing ever pans out. Longer-term investors would be well-advised to continue focusing on the prospects for Gen-Probe as a stand-alone company and leave the rumors to the traders.

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