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 Brazilian oil giant Petrobras (NYSE:PBR) (NYSE:PBR.A) rallied more than 13% today on surging oil prices and reports that Brazilian President Dilma Rousseff will ask for the resignation of company CEO Maria das Gracas Foster. 

So what: The bump in oil prices will help Petrobras much more than many of its peers because so much of its output is tied to higher-cost production in its massive offshore oil fields. With the price of Brent crude jumping by as much as 7% to more than $58.90 per barrel, you can be sure Petrobras' shareholders would celebrate.

The other big reason investors are excited is that it looks as though Foster will be given her walking papers by the company's largest shareholder, the Brazilian government. Just about every member of Petrobras' executive suite is getting swept up in a corruption scandal that involves kickbacks to management and politicians on more than $20 billion in contracts the company handed out in recent years. The situation is explained most elequoently in this comic strip from Bloomberg.

Now what: It will probably be quite a while until this corruption scandal is resolved, and it will probably take more than $59 oil for Petrobras to recover all the costs tied to its deepwater production program. These developents are a step in the right direction, but the company must also resolve other problems including its foreign-denominated debt and perpetual losses on domestic gasoline sales. For now, it's still best for individual investors to steer clear of this stock, even if it trades at an investor's dream valuation with a price-to-earnings ratio of 5.5.