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 mortgage insurer PMI Group (NYSE: PMI) jumped more than 10% in intraday trading on big volume.

So what: Shares of big banks such as Bank of America (NYSE: BAC) and Citigroup (NYSE: C) came under fire today as state attorneys general from around the country are turning a keen eye toward missteps the banks made in evicting delinquent borrowers. In the shadow of all of this is a glimmer of hope for mortgage insurers like PMI -- namely, that they will be able to put some of their losses back on the banks.

Now what: The entire mortgage insurance industry has been steamrolled by the housing collapse. However, as I noted earlier in the week, some big-time investors have started to jump on shares of PMI and others like MGIC Investment (NYSE: MTG). If the insurers are able to recover some of their losses from the banks, it would undoubtedly be a big positive, but it's unlikely that banks will just roll over and allow that to happen. PMI is still in a pretty precarious position, so investors looking at PMI should have a very clear understanding of exactly what they're getting into before they take the plunge.

Interested in more info on PMI Group? Add it to your watchlist by clicking here.

Try any of our Foolish newsletter services free for 30 days. True to its name, The Motley Fool is made up of a motley assortment of writers and analysts, each with a unique perspective; sometimes we agree, sometimes we disagree, but we all believe in the power of learning from each other through our Foolish community.

Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or on his RSS feed. The Fool's disclosure policy assures you no Wookiees were harmed in the making of this article.