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 Pioneer Southwest Energy Partners (NYSE: PSE) jumped 21% today after getting a buyout offer.

So what: Pioneer Natural Resources (PXD 0.30%) has offered 0.2234 shares of stock per share of Pioneer Southwest Energy Partners. The company already owns 52.4% of Pioneer Southwest and 100% of the general partner so this would just merge the entire company.  

Now what: Pioneer Southwest is trading for $31.85 as I am writing, and Pioneer Natural Resources at $137.50 investors have pushed the latter past the offer price. Essentially, traders are betting on a higher offer in the future. At the very least I would take some gains off the table today, because a deal could fall through and there's no guarantee a higher offer will be made.

Interested in more info on Pioneer Southwest Energy Partners? Add it to your watchlist by clicking here.