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 GeoResources (Nasdaq: GEOI) have climbed 20% today after the company announced it was being purchased by Halcon Resources (NYSE: HK) for $1.0 billion.

So what: The terms of the deal call for GeoResources shareholders to get $20 per share in cash and 1.932 shares of Halcon for each share of GeoResources they own. At Halcon's current share price, that's worth about $39.61 per share to shareholders, or a 7% premium from GeoResources' current price.

Now what: There is still some upside on the table if you want to hang on for the extra premium the market isn't pricing in. If you're supremely confident the deal will go through, you could also short the number of shares of Halcon you will own when the deal closes and stay long GeoResources, locking in Halcon's pop today. No matter how you slice it, this was a good day for shareholders and gives Halcon more assets to work with as well.

Interested in more info on GeoResources? Add it to your watchlist by clicking here.