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 EPL Oil & Gas (NYSE: EPL) jumped 30% today after the company agreed to be bought out.

So what: Energy XXI (NASDAQ: EXXI) offered $1.53 billion to buy EPL in a deal that would create the biggest publicly owned independent on the Gulf of Mexico shelf. Shareholders are being offered $39 per share in cash or 1.669 shares of Energy XXI per share of EPL, as well as a mix of cash and stock.  

Now what: The pop today is more than a dollar less than the cash offer, which is consistent with the risk shareholders take in buying shares and holding to get $39 in cash in the future. There's a little upside in hanging on and there's always the possibility the price is increased, but investors are taking a risk if they hang onto shares now and the deal collapses. I'd cash out and move to the next opportunity, because the premium investors have gotten today is too good to pass up.