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 Integrys Energy Group (NYSE: TEG) jumped 12% today after agreeing to be acquired.

So what: Wisconsin Energy Corp. (WEC 0.82%) agreed to buy Integrys for $9.1 billion, including assumed debt. This would create a larger gas and electric regulated utility in an effort to fight off new competition from alternative energy sources. Utilities have been combining across the country to keep their current businesses intact as they see emerging threats from other energy sources.  

Now what: Under the terms of the deal, Integrys shareholders will get 1.128 shares of Wisconsin Energy and $18.58 per share in cash. So the reason shares haven't jumped the 17.3% premium from Friday's closing price is in part because Wisconsin Energy's shares are down 3.4% today. Considering the small premium, I wouldn't be surprised to see a higher price eventually -- but if I were a shareholder I'd take some chips off the table, because mergers aren't guaranteed to go through. Taking profits on today's bounce is a good idea.