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 electricity generator UNS Energy (UNS) jumped 28% today after the company agreed to be acquired by Fortis.

So what: Canada's largest investor-owned gas and electric utility will pay $60.25 per share in cash to acquire UNS Energy. The transaction will require the approval of shareholders and regulators and probably won't be completed until the second half of next year.  

Now what: For UNS Energy shareholders, there's not a lot of upside to hanging onto the stock now. It may be a year before the deal closes and there's only about $1.75 per share in upside at the current offer price. By selling now you take a nice gain and avoid any snags to the deal. That's what I would do if I owned shares.