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 car renter Hertz (NYSE:HTZ) dropped 10% today after the company reported earnings.

So what: Third-quarter results were actually better than estimated. Revenue was up 22% to $3.07 billion, meeting expectations, and adjusted earnings per share of $0.73 were $0.02 ahead of estimates. The problem is that Simply Wheelz didn't make proper payments after acquiring Hertz's Advantage brand and is filing for bankruptcy. Hertz had to put $4 million away to cover amounts due but not made.  

Now what: Management is exploring its options for recouping losses on the Advantage sale but doesn't seem optimistic. It took a $40 million charge related to the sale and the company probably isn't first in line in a bankruptcy court. I don't think this is a reason to panic today and actually view this as a buying opportunity for long-term investors. Shares trade at just nine times forward estimates and demand for rental cars is high right now.