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 OM Group, Inc. (NYSE: OMG) jumped 28% today after the company agreed to a buyout from private equity group Apollo Global Management LLC.

So what: Apollo has agreed to pay $34 per share for OM Group, and then it will sell off the Electronic Chemicals and Photomasks businesses for $365 million. OM Group will have a "go-shop" period where the board of directors can actively solicit other bids that could potentially increase the value of the buyout. But there's no guarantee that a better offer exists. 

Now what: Given the fact that shares are already trading near the buyout price, traders are confident that the worst-case scenario is that the current offer gets executed as planned. While there may be some upside if a new bid emerges, the premium of 28% from Friday's closing price is probably enough to scare off most potential bidders. I might take some or all shares off the table after this offer today, because I think the biggest risk is that the deal falls through, and with shares trading at nearly $34, it's not worth that risk given the limited upside.