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 Penn Virginia Corporation (OTC:PVAHQ) jumped 15% today after activist investor George Soros became an active investor.

So what: In a filing, Soros said he increased his stake in the company from 8.2% to 9.2% and wants the company to explore strategic alternatives. But he also said the company is well-managed and wants management incentives to be increased.  

Now what: Soros isn't a new investor in Penn Virginia, and the increased stake indicates that he thinks management can make moves to unlock value if it wants to. I also thought it was interesting that he didn't seem to have any interest in shaking up management, specifically saying that they were doing a good job. Buying solely on Soros's stake isn't a good idea, but if you're looking for a reason to be more bullish on Penn Virginia, I think this is a good reason. Soros has a good history as an investor and may be able to stir up asset sales or acquisitions that could drive more value.