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 MBIA (NYSE: MBI) saw a rare sliver of daylight today, jumping as much as 11.2% on fairly average trading volume.

So what: Like penguins and coyotes, the mortgage insurers tend to travel in packs, and that's what we're looking at today, too. What looks like MBIA making a solo move turns into a stampeding herd if you zoom out to include the last hour of the Tuesday session. In that light, MBIA peaked at a 16% gain while The PMI Group (NYSE: PMI) jumped 19% at most; both MGIC Investment (NYSE: MTG) and Radian (NYSE: RDN) soared as much as 18%. MBIA was just a little late to the party.

Now what: With mortgage interest rates falling and closing fees on the rise, not to mention the Bank of America (NYSE: BAC) drama over Countrywide drawing to a close, it's not hard to see why mortgage insurers are heaving a collective sigh of relief -- risks are being worked out of the system. That being said, these three musketeers have lost between 37% and 94% of their value in 2011. You have to have a big appetite for risk to consider buying any of them today.

Interested in more information about MBIA? Add it to My Watchlist.